I'm the OP and am following up on this. We went to the pediatrician today and - so happy - the doctor brought it up very gently and while she was plotting her growth on the growth chart. I had sneaked a peak at the chart earlier and saw that she was 5'2" and 152.

So, I was 12 pounds off my estimate. The doctor then came out and spoke to me on the QT. It was a good conversation and she was just very empathetic and supportive. I spoke to my DD on the way home about some strategies and will leave it at that. Or, at least I'll try. I'm giving her some South Beach food plans because my doc suggested it was a good plan and I basically eat this way too. I'm also hopeful she will increase her activity level. I appreciate the support.