I may have a unique perspective. My oldest son is like your friend's girls. My second son(17 mos younger) is like your daughter. When your child accomplishes so much and is so good at everything, you DO feel a lot of pride. I try very hard not to brag. I am proud, but his athleticism, grades, etc speak for themselves. However, I am equally proud of my second son. He isn't the star athlete or get the grades his brother does-although he is very smart. But, he is absolutely a joy and has so much to offer the world. He will hit his own stride and be amazing in what he chooses to do. My heartbreak is that things don't come as easy to him as they do his brother. I can't imagine being _____'s younger brother. I ask him about it and he says it doesn't really bother him. It also bugs me that success often is tied in with the mainstream popular activities like sports and popularity. I'm not going to be able to change that in my lifetime or theirs. But, there are some other things you might consider:
To the outside person, my oldest may seem to have it all. But, they don't know about the intense pressure he puts on himself to please coaches/teachers and the social pressures he feels already. It's going to be a life-long struggle for him. People expect a lot out of him. His dad and I don't put that on him, he does it himself. THis may be happening with your friend's girls. They may not talk about that. You aren't in their home - there may be struggles they have that you wouldn't want for your daughter.
Also, very soon these kids will start to even out. The advanced kids and the more average kids will merge more. What's more, is that your daughter may find something that she is passionate about that has nothing to do with what these girls are doing. Music, art, writing, etc. That is something to be very proud of. She hasn't blossomed yet, but is still trying to figure it all out. I know you know all of this. It's hard when I see the boys in my second son's grade breaking out and leaving him in their dust. These were boys he was once very good friends with. They just aren't interested in the same things, now. They would rather hang out and play catch with his older brother. Ugh.
You know your daughter is special. Your friends are just as proud and that's what moms do - we talk about our kids. If they are supportive of you in every way, you may have to just keep smiling and bear it. Talk about the book series your daughter just loves. Or, how she did the dishes without being asked. These are accomplishments!!!! As far as getting her into stuff, keep offering different things and maybe one will stick for her. I wish you luck!