The only suggestions I can think of for now are:
-Offer rats in the 70-90 gram range. Sometimes they will refuse prey that is too large. I used to have a 4.5ft, 2400g male that wouldn't touch any rat over about 110 grams. Also, make sure you are thoroughly thawing and heating up the rats. If the snake isn't interested in thawed, try heating it up to 98F-100F. This is the rats natural body temp.
-Try raising the ambient temp up to about 80F.
-Put her on aspen bedding. I know it sounds crazy, and I don't know why, but sometimes switching a snakes bedding to aspen helps. A layer of 1/2 inch to 1 inch thick is best.