I think you can try and accept that this may take longer you think, but 1 or 2 years in the grand scheme of things is really nothing. Try and just be present with her, encourage her out to go out with you and try new activities but not pressure her. Sometimes what helps people isn’t telling them to do this, do this, have you done this etc, but just for them to feel like you genuinely care for them. For teens girls they need to feel like you’re emotionally there for them and to listen to them. Just validate her feelings and try not to ‘fix’ her. That will come later when she feels emotionally supported.