I'm not sure how familiar you are with all the ins and outs of the guardianship issue but just ... it might well be a fair bit more challenging to get guardianship of the [higher functioning daughter] then it would be for your other daughter. I'm not suggesting that your one child doesn't require guardianship or that you shouldn't apply for it, just that obtaining guardianship (with or without the services of a lawyer) could be a fair bit trickier when it comes to our higher functioning kids.
Fist, I might suggest you read my posts regarding guardianship on my blawg (if you haven't already) ...
My other suggestion would be that you consider attending one of my presentations on the issues of guardianship, powers of attorney, personal directives and Henson Trusts (and if you are not familiar with Henson Trusts that is something you really need to know about when it comes to leaving any money for your daughters, in your Will or in any other form). I have been giving these for various disability organizations recently and you might find attending one of these free sessions helpful in clarifying your and your children's situation, including whether guardianship is the best option for both children or whether there might be some other legal tool available to accomplish what you need.
The next presentation I am giving is for the HACL (Halifax Ass. of Community Living) on January 29th at 1:00 in Halifax at the Keshen Goodman Library. They tend to run around 2 hours with me talking for about 1 1/2 hours and about 1/2 hour for questions. If you can't make that presentation, but are interested, I could let you know when I get a date for another one.
All that being said, if you are really comfortable that guardianship is what you want and need, I can offer you the Nova Scotia Legal Guardianship Kit, which I created to help parents, such as yourself, to obtain guardianship of their challenged children without having to incur the costs of retaining a lawyer. The cost of retaining a lawyer to bring a guardianship application can be very prohibitive for most families (I am hearing a range of $3,000 - $6,000) which is why I created the Kit. In many cases (especially those where the child is very low functioning), I believe it is something that parents could do on their own (if they are so inclined) if they had the necessary background knowledge.
The Kit provides all the precedent documents you would need to file with the Court, along with an explanation of what each document is and how to fill it out (giving as many different examples as possible) as well as explaining the how (process) and why of obtaining guardianship and what a person's obligations are once they have been granted guardianship. I am currently offering a hard copy of the Kit for $315 (which includes $15 shipping anywhere in the Province) and hope to eventually get set up so parents can download an electronic version, which will sell for $250.
I should mention that one other option that might be open to you (as opposed to either hiring a private lawyer or going it alone with the help of the Legal Guardianship Kit) is retaining a Legal Aid lawyer. You, personally, may or may not qualify financially for Legal Aid, but one possible way around that could be to have your child made the client. In your case, and I am thinking of your daughter with Aspergers - if she was agreeable to you obtaining guardianship and was considered competent enough to instruct a lawyer (and it's not a real high standard of competency to instruct a lawyer), that might be an option to consider. Then again, as long as you would be going to court to apply for guardianship of one child, you might feel that you might as well just do both. I go into a little more detail about the Legal Aid option in my presentations which is another reason that I would really recommend that you consider attending one.
PS As an aside, I feel you are very smart to try to move on whatever you decide to do as soon as quickly as possible now that your children are 19. I know some parents feel that there is no urgency as it is unlikely that anything bad would really happen or could go wrong, but I have seen two situations recently - one in which the parents were very happy that had applied for guardianship as soon as their daughter turned 19 when later that year they were dealing with Community Services on the issue of placement and one where the parents did not move quickly for guardianship and a total nightmare situation developed in which a family of very shady characters essentially took their son away from them and obtaining guardianship and protecting their son turned into a full-blown court battle - that have really driven home for me how important the issue really is.
And with regard to the question of the necessity of guardianship in order to open a RDSP …
The answer to that question (the necessity of obtaining guardianship) sort of depends - both on your child's age and just how mentally challenged she is.
If your child is under 18, you as the parent can open the Plan and remain on as Holder even once she turns 18. If she is considered legally competent when she turns 18, she can be added as a Holder at that time, but you as the parent will also remain a Holder.
If your child is 18 or older, the federal gov't considers her to be an "adult" and, if she are considered legally competent, the only person who can open a RDSP for her is hers. The answer to whether or not a person would be considered legally competent can sometimes be a very gray one. It's sort of a medical/legal determination and although your perspective and knowledge of your child's abilities would certainly be considered as relevant factors, it's only part of what goes into the determination. In both the above scenarios, your child, of course, whether or not she is a Holder of the Plan, would also be the Beneficiary of the Plan.
If your child is between the ages of 18 and 19 you get stuck in a bit of a hole. Although considered an adult by the federal government, the provincial government would still consider her to be a minor - meaning that, if she was considered legally incompetent, she couldn't open her own RDSP and no one would be able to apply for guardianship of her until she turns 19. Effectively that means that there is a year in which it is impossible for a RDSP to be opened for her.
In any event, bottom line, not knowing your daughter at all, I have no idea whether she would be considered legally competent.
I can tell you, however, that on a practical level, if the financial institution ... is questioning your daughter's capacity (likely only on the basis of [the diagnosis]), you are most likely looking at a more complicated situation where you are going to have to "prove" your daughter's competency to the Bank before they will let her open her own Plan. Which, I think the process you would go through to "prove" competency would be very similar to the process involved in proving incapacity for a guardianship hearing - I imagine they would require, at a minimum, one doctor's letter setting out their opinion that your daughter is competent (for a guardianship, application you need two medical doctors setting out their opinion that the person is incompetent).
But I think it's important to realize that there may well be other reasons why you might want to consider guardianship for your daughter, outside the RDSP issue. The issue of guardianship has really come to the forefront lately with the introduction of the RDSP but, in my opinion, it's really something that we, as parents, should be looking at more closely for a variety of other reasons (disclosure of medical information and dealing with the Dept of Community Services just being two possible examples).