No experience of this, and I'm by no means an expert, but at this age (which is still on the young side for walking), I personally wouldn't worry at all. There are all kinds of benefits that LOs get from crawling that they don't get from walking, so if your LO spends a bit more time crawling, that is probably a good thing!
If you're concerned though, then I'd prob see a doctor. Maybe she's grown a bit and the change in size/weight has made walking more difficult for her?