C.G.
Well, it sounds like you already know why your daughter is short... you and your husband are short. The chart goes from 0 to 100 because someone is at 1 and someone is at 50 and someone is at 99. There is no point in having a chart if we assume everyone below 10% has something wrong with them.
The purpose of the chart is to look for a trend in growth. If your daughter was at the 90th percentile until six months ago and lost 5 pounds and stopped growing I would be concerned. If she was at the 10th and slowed a little or has always been around 5 I wouldn't be concerned.
I would look for a new doctor. To be blunt, your doctor apparently doesn't know how to use the charts and isn't able to use other factors like heredity and nutrition to figure out that your child is just a small person.
Now if there is some other issue here like chronic diarrhea or anemia then there may be a problem that warrants further investigation.
BTW, I have two "small" children- my daughter is 3 and she weighs 23 pounds. So this is kind of a touchy subject for me. Good luck.