So.....I've been a bad mom and hadn't started "tummy time" until just today. So I asked my husband to put her down on the floor when he got home from work. Within 10 seconds she's over on her back. Being a typical wife, I tell him he must not have put her actually flat on her stomach (maybe he put her on her side by mistake?) so I asked him to put her back again. Well, I watched super close this time and she rolled right over again! Of course, my other 2 were more typical with their milestones so I didn't think it was a big deal to wait on tummy time. Who knows, she could have done this weeks ago if I just tried.