Social anxiety can be crippling. it may take more than medication and therapy. If you do switch to online schooling, do ensure that she gets some social interaction. What worked for us, was to include the child in shopping trips to buy groceries. Having the child help with shopping slowly builds up their familiarity with something she is going to need later on. We also used comparison shopping to help with maths skills, so it didn't matter that we went shopping during school hours. The cross-section of people she will meet if you go out during school hours, is different to the crowds of kids who hang out at the shops after school. It might be easier for her to cope with adult interactions. Start small - have her interact only with you while out shopping. Send her to get this item or that, in the same store. Then have her (with you there) process the goods through the checkout (ie interact with the staff member at that level). Over time, build up what she does. Also don't forget to reward her - if she has helped you, has really made an effort, buy her a pair of earrings or a bottle of nail polish. Something inexpensive that catches her eye that will remind her, when she uses it, that she had a success.
We found the switch from mainstream education to correspondence to be far less stressful. No nagging to get off to school, no having to cancel my plans to rush to the school to deal with the latest crisis. I could go back to planning my days and be fairly sure that my plans would not be derailed. We did fun stuff together, but he also got a lot more schoolwork done. Correspondence is outcome based, so the school technique of letting the work slide and it would eventually go away, did not work with correspondence. It all had to be done, they tracked it. If he had a problem or did not return a unit of work that was due, they would call him and talk to him about it. Or they would email.
We did the same thing with difficult child 1. He was older when we made the change (17) but even then, his social anxiety meant he could not make a phone call. He could talk on the phone once I dialled and made sure the right person was there for him to talk to, so over time he began to get more confidence in telephoning his teachers.
What social anxiety kids need, is a series of small successes. You start at the level the child can handle, and work from there. But at the same time, work towards life skills.
It is much easier. Trust me.
Marg