My oldest daughters have severe anxiety maybe you could try to start a small group at home first till she feels more comfortable then slowly move to some place close by where there isn't alot of people low pressure maybe even a hobby group to start.

I know it could be healthy for her too, as isolation is not good for mental health. My 20 yr old son who was not diagnosed until almost 17 has been difficult w socialization his entire life. Over the past 1.5 yrs he has improved. What helped him was the right medication with the right therapist as together increases the chance of a therapeutic outcome that will improve her functioning. We had all combos: wrong meds and wrong therapist, right therapist but wrong meds and right meds but wrong therapist. Until we got right meds with right therapist there was not much improvement. When an autism psychiatric specialist prescribed Namenda (used for Alzheimer’s) my son started displaying more prosocial behaviors. He also takes a small dose of Celexa to help reduce anxiety. You really need a skilled specialist in spectrum disorders. It is so strange to hear him talk! Group stuff is still hard as he prefers one on one encounters. I find making him think it’s his idea works best as no one likes to be forced or told what to do. So language used is very important as to whether he will come around to any idea - not just group activities, but especially group activities because that extra fear/ anxiety. It is not easy - trialing medications and therapists until you get the right combo is exhausting and frustrating since it can take years and can make things worse instead of better. Support groups usually don’t work for young adults. I find it’s better to back into a group - meaning find one person she likes and then add another that fits well with her and now you have a small group of three. She doesn’t need a large group and people who work w young adults w aspbergers say this is the best way to get them to participate in a group. Finding a group and trying fit them into it usually fails because there are too many people and too much variety in the people. All she has to do is find one person in the group she doesn’t like and that will be it. Tried and failed in this approach many times. To make it even more trying my son before Namenda would not allow anyone to come over to the house as he found it threatening. His house was his safe space from society. Now he is in college living alone in an apartment and has one friend who he met in math class (not surprising he clicked w another person in college algebra rather than in English) and his friend comes over to his apartment occasionally for dinner and video game playing. I know how extremely hard it is to find good psychiatrist and good psychologists (recommend clinical PsyD or PhD w spectrum disorder treatment experience) rather than master level. She needs someone more clinically trained as treating spectrum disorders is complex. Good luck to you!!

Sounds like she needs a good therapist one on one plus small group therapy. Key is to find the right person. Maybe you need an intervention if you can't convince her to go.