I think most children learn better one-on-one. It's just not practical all the time, and sometimes they do use an activity for the social aspects. Not all that one-on-one activity needs to be by a "professional" though. A dad or mom taking the kid out and practicing throwing a ball, or working on their swimming.
If your child wants to get good at a musical instrument I do think one-on-one lessons with qualified instructor are important. Group lessons or a performance group are a different aspect that can in addition be helpful but it's different. But for the basics a group lesson is going to have a lot of hurry up and wait. As a child I took piano, one private lesson a week and one group. Honestly I don't remember getting much out of the group lesson. My son takes band at school, but I spring for a private instructor once a week. If your daughter isn't enjoying the group lessons, then I would probably try and look into something else.
