Michelle is one of the legitimately toughest of the WWE alumni, and I think she could handle either of the Bellas. However, barring some serious stroke of luck, I think the two of them together could handle her pretty easily. She might hold her own for a while, but eventually the numbers game will let them take her down and take control. Once she's on the defensive it would just be a matter of time before they put her away.
-JM