" wrote in
ps.com:

Just because its never broken before doesn't mean it never will!

If she goes to a ticket office, they can call oyster helpdesk and
confirm how much prepay is on her ticket, and provide a duplicate.
SNIP

I've heard from someone that the old tickets (and this is one of the first
batch) won't let you do that. I'll let her know.

Thanks for the tip though.