My 2 year old is significantly shorter and lighter than her peers. should i be concerned?

Possibly concerning: When a child is shorter and lighter that his/her peers, this may be normal or it may be a serious condition known as failure to thrive. This depends on several issues including ongoing medical problems, medications, the child's actual age compared with the actual age of the peers, and an evaluation of the child's growth chart from birth to present age. See your family doctor or pediatrician soon.

Possibly: I agree with my colleague; but would also ask that you consider the height(s) of you, your spouse, and your parent/family. The stature of the "family" does play a large part in the height of the child; and should take the fear out of the equation if the child is eating and otherwise developing normally. Petite parents have a good chance of having petite children; exception apply of course.

Maybe: It is basic that 10% of normal kids will be shorter and lighter than 90% of kids the same age. That diversity is part of our genetic makeup.If this is a pattern your kid has followed for 2 years, it is more likely to be her normal. If she started out average and is now much different, it is likely a problem.This is something that pediatricians consider every checkup.Talk it over with doc.