You do not need a lawyer for Canada - I have relatives in Quebec tho it does depend on the jurisdiction I believe and the amt? Sometimes, it is wise to have a lawyer even in US small claims courts for large amts.
I was going to say I agreed with GoldenKitty45 over calling and pretending to be the foster person. That would make you look bad in the eyes of the law if yu did end up in court and wit privacy laws enforced these days, you'd have a tough time of pulling it off. And ethically, it's just wrong.
In any case, I am happy to hear you have made progress! I would get there asap though to ensure your cat is fine. Next time, get references and make sure the sitter is bonded or is at least somene credible. This person may very well be but I do not like all these excuses.
I have discovered in my new vet practice that people actually are cruel to third pets (or their children are!) and just like parents who abuse their children, they lie about it. Cats - unlike children (A roommate in college is a social worker now). They will claim their kitty was hurt by jumping from something when you just know from looking at the ultrasound or the Xray that this was NOT the way an injury occurred. We had heard that in vet school and there were a few while I was doing my internship and I still work in the univ's ER now and then (they are short staffed amazingly and call me in often - like don't have enough to do, lol) but I never dealt with their humans. Now I have to and I confront them with it.
I know this is a digression and I apologize for that but those excuses sound familiar and so if I were you, and it may very well be nothing and this person is OK and I am basing my response on these recent experiences. You should get a contract with her when you go too - just explain you forgot when you brought your cat over (too much on your mind, whatever) and also you might think of having kitty injected with a microchip so anyone will know without a doubt he cat is yours.
Also re emails- they are useful in court and nothing really is private online. (My bf is in IT and the subject interests me as well now, lol ) So, her ISP 'Hotmail or not- would tell anyone what IP was used to send the email and any forensic computer person can figure out where she is from given enough info. (Especially when you have a phone number).
I hope your cat is fine and am glad to find the result of all this is GOOD news!!
I would like to see laws that