There is a problem here, a snake that size should not be going off food, that is normal for adults, not hatchlings which is the current size even though she is 9 months old. My 9 month old snakes are in the 600-800g range to give you an idea how far behind yours is. You're going to need to get her eating consistently weekly. That is by all means, if you can't get her to eat f/t then it's time to give her whatever she'll eat, live mouse, rat, asf, basically whatever she'll take and stick to it every week until she gets up to a healthy weight at least. Also make sure you are offering the right size meal. I feed mine rat crawlers at that size. Look at the sticky about getting your hatchling to eat and follow it exactly!