Should I be worried?

[jcarter]

DD is nine months old and hasn't gained any weight since early December. We meet with a public health nurse twice a month so she gets weighed often. She is growing in length, is doing well developmentally and seems otherwise healthy. It just doesn't seem like this long of a plateau would be normal. Is this just a case of having too much data, or should I really be worried? She was gaining steadily before this...