Yes anal sex can be very erotic for most women if it is done correctly.
Perhaps she is sensing you are a man in leading her more now???
Using lots of lub and making sure she is totally relaxed is one key.Massaging the g spot is another way of allowing a lady to have deeper orgasmic experiences.
At times I have spent 30 minutes or longer doing a vulva massage. Combining anal and g spot massage can be pretty mind blowing.
Maurice
Find and locate the male g spot and the
male g spot diagram