Hun, for her to be over a year old, she is very small.

From the picture and the size reference next to the mouse, she looks to be a little over a few months old, when in fact if she was 6 months old LAST April. For her to be around a 1 1/2 old... I would expect her to weigh close to if not over 1000 grams. She looks to weigh about 250 grams...

I would slowly increase the rate she is eating, from once every two weeks, to once a week, to maybe even 5 days. Check and double check your husbandry, and most importantly take her to a qualified Snake vet for an exam and a fecal check for parasites.

An experienced reptile vet will be able to help you move her prey size up with recommendations without shocking her body and possibly hurting her.

I don't expect she will grow to a normal size, since she is well past her baby stage. I have no experience with snakes that old and so small, I'm just assuming. Please keep us updated!