if we were to create a doctor sometime, it'd have to be one with the title Doc Euthn. 

Astridh/Eydis & Ariadne/Idalia probably won't get along all that well. Especially not Eydis/Ariadne. They have very different mentalities. And one's a former Goa'uld, while the other is a trueborn Tok'ra. Not that any of the crew will know the fact that Ariadne was a Goa'uld once.

The most notable differences that might make someone really experienced suspect something about Astridh is this:
1. She doesn't quite look her age.
2. She doesn't really get sick.
3. She's unusually strong.

The last two are hardest to tell, though. Good health can lead to the first, and the second can be concealed in a fit body.