Uy, naiintindihan ko ang worry mo mama, pero this is really something you should ask your pedia about soon, baka kailangan niya ma-check physically para ma-rule out if there's any concern sa spine or development niya. One of my mum friends noticed something similar sa baby niya at turns out okay lang siya, but better safe than sorry talaga, lalo na when it comes sa bones and posture ng little ones. In the meantime, make sure hindi ka nag-sit up baby mo too early if she's not ready pa, let her lead yung milestones niya, okay?