Yes, you can check out these two organizations which have local groups:
https://www.girlsontherun.org/
and I also recommend this summer program in MA: https://sbschool.org/summer/debate/
My sixth grade daughter really enjoyed the middle school version of Girls on the Run, called Heart & Sole. She was the only new girl at first so it wasn't easy to begin with, but the coaches did a good job helping the girls connect. Thing is, it centers around running and culminates for the fall with a 5k this Saturday. I believe they start up again in the spring, but I'm not 100% sure. I don't think they meet in winter.
Really hating my daughter's self doubt and second guessing and my encouragement doesn't seem to be resonating, so I'm looking for external help. Has anyone had any success with a group setting where girls can talk about their feelings among their peers and learn how great they are?