She can also play the cello with the less-than-elite groups at school or elsewhere. Get a good, but less demanding teacher (maybe saving a few bucks along the way). She can practice minimally and still enjoy the social side. I did that with violin (just the school orchestra, practiced rarely, no private lessons) and had a lot of fun and made friends.

Let her choose. AND whatever her choice, just let her participate at a level that she finds enjoyable.

There seems to be an undercurrent of pushing her to be in the "elite" group as you were. Just let her play. Whose idea is taking lessons? My orchestra DD takes lessons, but at her request. It is not required for her orchestra class at school, and if she wanted to drop them, I would be fine with it. She is not a virtuoso, but a decent violinist who plays her part well and enjoys her time with the group.

Being in the orchestra, or the band, or the chorus, or in theater definitely gives you a friend group in HS. If she is happy hanging out with her orchestra pals, don't force a change on her.