I don't really see where your peds concern is. Someone has to be in the 30th percentile or there wouldn't be a 30th percentile. Are you and your husband tall or thin? It would make sense for your daughter to have the same body shape.
It is normal and expected for children's weight to plateau once they are able to move around. The time to become concerned is when there is no outside reason and a child in the upper percentiles drops very low. Your child is still well within the normal ranges and in fact is pretty average.
I would seek a second opinion from someone who is a little less interventive.
Here are some quotes from a website about the CDC growth charts:
"In general, any weight or height between the fifth and 95th percentile is considered to be in the range of normal. If a child falls outside the normal range, it means that she is heavier or lighter than most other children her age. It does not mean that she is abnormal in the sense of being sick! " http://www.drspock.com/article/0,1510,4491,00.html
"The percentile curves on these charts represent what percentage of children are of the same height or weight. The 50th percentile represents the median height or weight for each age group, so that 50% of children will be above this point and 50% will be below it. If a two year old boy weighed 24 1/2 pounds, then he would be at the 10th percentile for his weight at this age. This means that 90% of two year old boys weigh more than him, but it also means that he weighs more than 10% of children of this same age."
http://www.keepkidshealthy.com/growthcharts/