Well, I would wait until after she sheds, and maybe try to give her a meal before. If she's in a new place, she should get about a week to settle in. Then try all you want. She could retain sperm from both males. I even think there was an instance with an egg that had traits from two males. I could be wrong though, and only heard it once. But, if you do happen to end up with some hets, and they prove out, having some caramels come out of a bad deal isn't a really bad thing.
On a side note, if you purchase a new snake (no matter where it came from). Always quarantine. Especially from a show. The breeder might have healthy babies, but they can pick anything up from a show. I've heard horror stories about mites. And, the to and from places were both clean.