M.W.
Each child is different, and hits the mildstones at different times. my first son crawled than sat up and my youngest is the same he is 7 mon and not sitting up but doing the army crawl, his twin brother is sitting at 6 m and hardly crawling but likes to roll to get where he wants or demands to be picked up. she will get it just keep helping her sit up to work on those stomach musles