A.F.
Dear Sara, I am so sorry that you have been a victim of Harold Z's hatred and immaturity. He has been harassing mama's on this site because he probably doesn't have anything better to do. PLEASE don't let him steal any of your day. He is powerless!!!
EDIT! I am so glad they deleted his response so quickly!
As for your question......
I would take your daughter to a chiropractor for a second opinion. Your doctor may be right that there is nothing wrong but it's always reassuring to have another opinion!
A chiropractor can tell straight off if there is another issue affecting her than just looking or testing leg strength. If you are not familiar with chiropractics for infants, they do not "crack" any bones in babies! :) they are very gentle!
Blessings on you and I hope you find an answer!