I hope someone else comes along with a better answer. I have never had one go that long. To me a jumbo rat seems really big to be eating weekly.

If you have been keeping her in the tub during the strike, maybe try letting her out to get some exercise..?

How does she look? Did you get a weight when you first got her and what's her weight now?

My 2 bigger girls are 6' - 7' 8-9 lb
I feed them a LG every 2 weeks or a med every week. I'll mix it up for them.

I wouldn't give up on her just yet.