Here's an example of how you can do rankings and still keep it positive:
viewtopic.php?f=401&t=32946It's not just the OP that sets the example - I read through all 15 pages and didn't see a single post that could be construed as being negative to any player's ability. Bracky did a bunch of these rankings back then, and they all were similarly professional. I'm not suggesting that anyone should be expected to be this professional - he was one of a kind - but it's not a bad idea to learn from the best.
This is all under the broader heading of "getting it" and making this the best experience it can be for your DD and the rest of the girls playing. Going back to the list I linked, I've since coached against a number of those teams. Won some, lost some, but didn't have a single bad experience. The coaches and parents that I interacted with all seemed to "get it", and I learned a lot from them.
You guys are lucky to have Coach P (Martin Garcia) in your division, even if your DD doesn't play for him. I'm sure that there are other great coaches, too, but Coach P is the best I've ever met in terms of understanding what this sport is all about and providing a great environment for ALL the players.