I think its events like this that start to show why the community has so many grievances against petco...(though we do have members that work there, that we love!)
From what I am seeing, working off that stuck shed would probably be my first worry, because I read above that she is now eating regularly every week? I would say that if that is/was the only worry, then you may not have to bring her to the vet currently, but a checkup to be safe is never something frowned upon, either.
As for the weight loss, do you have any recordings of what she was when you got her and what she is now, or was it just visual? I recommend at least keeping basic recordings of your snake, its a good thing to have if something bad does occur. I record weights after using the bathroom, in blue/shed days, and each feeding, as well as any changes that may occur to husbandry (new hide, or in the case of a few weeks, new rack) so I can see if that had anything to do with recent problems.
Other than that, welcome to the forum! Shes a very beautiful snake, and I hope she feels better soon!