I'm thinking that probably explains it if it isn't just her being skiddish right now...try covering the warm side of the tank with a towel so that she has some cover to feel more secure and see if she goes over there. I just read this snake book and was reading about how insecure snakes get scared seeing everything going on outside of the tank...and to cover the tank with a towel to make it more secure for them...of course you want to leave air circulation. I always cover part of the tank for my eastern male to eat...he won't eat if he can see people....you may want to try that for feeding her too. I also cover part of my other tanks...just to make the snakes feel more secure. I know other members on here have red-sided garters...start a new thread tomorrow and ask about temp preferences for their snakes.