Tummy Time With Lennox

It's been awhile since I pulled out my camera and took some updated pictures of Lennox, aside from her monthly photo shoots of course.  She has been rolling from her back to her stomach since before she was even two months old but I can count the number of times she has rolled from her stomach to her back on one hand.  What is the deal kid?  It would make my life tremendously easier if she could roll both ways.  When she gets tired of being on her stomach and holding her head up she turns into a thrashing drowning victim until I come rescue her.  But I must say she has gotten so much better at pushing up while on her stomach.  She prefers to interact with her sister, her toys, and the dogs this way.  Hopefully she figures things out soon because I'm too nervous to move her out of our room to sleep until she can roll both ways.  Please, tell me she won't be in our room until she's 12 months old!