I think she's off to a good start, already having a hit outside of the US upon debut despite the fact that she's based in the US.
She reminds me more of Jessie J in terms of tone, but I prefer Rita.
P&B is slightly generic though, but her different style kind of makes up for that.
Rita is going to have to present something unique if she really wants to make it. Right now she looks too much like Rihanna (style/overall image) yet her music isn't nearly as catchy.
No. Shes pretty and has a good voice but that's about it. Rihanna has that distinct tone that sets her apart from everyone and made her the pop staple she is now.