To bring this to you from another angle - my DS1 who crawled at 6m, walked at 12m is dyspraxic. DS3 who crawled at 4m and walked at 7m is probably not going to be ready for school. I am still fighting with TT and he has some big time speech delay issues. He still does not hold a back and forth conversation with me at 4yo. A lot of what he says is illegible to everyone but me and DH. Everyone was certain when he started walking at 7mo that he was some kind of genius like my eldest sister who also started walking at 7m - admittedly including me. I tend to look at it as though I have failed him.

Not only is google not your friend, but anyone can publish anything online without censor. Is the information you are reading derived from years of peer reviewed study? Or just someones anecdotal observation which could actually be saying that in some cases parents are not helping their children with their milestones at all?

IF you see evidence that there is a delay with your DDs speech, seek help then. I don't think forcing her on her tummy is going to teach her anything useful, iykwim. Sit her down where she is comfortable and talk to her instead.