Since from your comment she appears to be in the UK, GDPR right of access still applies. She can get a copy of the data, even if not access to the account.
Your comment raises an interesting point: If I, a non-EU citizen who doesn't live in the EU, get locked out of my gmail account, would traveling to the EU and invoking GDPR be a viable way for me to force google to hand over my emails?
If yes, then I sense business potential. I for one would be willing to pay a lot of money to access my inbox.
I recall reading that it's 6 days of living in the EU until it "kicks in." I don't have a source or that and can't seem to find one, so take it with a pinch of salt.
