B.C.
She is 24 years old and an adult.
Is she incapacitated and are you her legal guardian?
Do you have power of attorney to make decisions for her?
Does she want to see doctor(s) to be evaluated?
Because if you have no control over her and she doesn't want to - you can't make her.
You want to have her diagnosed as Aspergers for what purpose?
Are you hoping she will qualify for receiving disability?
If she was a young child and had been diagnosed then - she might have received therapies to help her development - but she's 24 now and I'm not sure what would apply at her age.
Perhaps you and your daughter can find help at one of these sites
https://www.usa.gov/disability-programs
https://www.parentcenterhub.org/foradults/