My wife is worried. A friend of hers was robbed whilst on holiday in Barcelona. A bag containing their iPad (among other, less important things like passports and money - lol) was stolen. The husband evidently immediately contacted Apple who arranged, the next time that iPad was turned on, to wipe the memory. They subsequently received an email from Apple who said it had been turned on, and remotely wiped clean. My wife (and I to a lesser degree) have emailed this lady, sent photos, Skyped etc. and now my wife is worried that her personal info on her own iPad might have been compromised because the thieves 'would have been able to gain access to my iPad' using the other lady's info. Thing is, I use my laptop for Internet Banking, online shopping etc. as well as emails etc. She is now asking me whether we need to change security (email address/passwords etc.). To be honest I don't KNOW the answer but I assume there is little or nothing for us to worry about. However, I DID say that ABers would know the answer!!
Ask your wife if (had her friend's iPad not been stolen) she could, if she was so maliciously inclined, have accessed her friend's bank account, ordered items in her name and accessed her email, simply because they'd emailed each other or shared some photos.
If (as surely it must be) her answer is 'No', it follows that your friend (or anyone else with your friend's iPad) couldn't access your wife's accounts and emails.