Tony is a useless slimy scumfuck degenerate of a human being, and it should be no surprise he's trying to shamelessly extort someone for information in the most pointless, half-assed and lazy way humanly possible.
The best advice I can give you is: if she hasn't already mentioned her age somehow, claim your friend is 12 years old. Tell him she's your niece or daughter playing on the account if the birthdays don't match up (something about getting around all the arbitrary age limits that never expire.) Then tell him that you've screenshotted the entire exchange and you'll forward this undeniable proof that Tony tried to blackmail a small child for dubious reasons to Jumpstart.
He'll probably bail and close the ticket like the absolute coward we all know he is, but there's also a chance he'll go "oh fuck" and drop the charade and instead ask for more traditional proof your friend didn't cheat. Then you can just try to contact Jumpstart directly, cite the morally-reprehensible coercion of a little girl on a pet website designed for children and ask for the account that way.