I dont think your over feeding her, if she is pregnant she will eat lots anyway , but i agree she has been brought out of season by one method or another, as Skycat sayes they dont naturally come out of season until the days are shorter later on in the year
Feed her as you are doing, dont reduce her intake, she must be hungry or she wouldnt eat , one thing to bare in mind is ,stashing food, check her cage all over as she could be stashing it