...then she held her mouth ajar for a few seconds longer than I wanted...
I think she just forgot to check with you about how long she should hold her mouth open.

Seriously though, I don't think this is cause for a vet visit. At all. You run a much higher risk of causing stress by taking her on a road trip and getting her poked and prodded by a stranger than by simply keeping an eye on her for a few days to make sure she didn't injure herself by hitting the side of the tub. I'm sure she's totally fine.

I know you're stressed and paranoid about these guys after all you've been through with them. I hope, in time, you'll finally be able to relax and enjoy them like any other healthy, beautiful snake in your collection.