That's such a weird quote (if accurate), I wasn't aware of Jo's little fruit machine addiction. Anyway:
a) "I think I've just about broken even" = "I'm ten grand in the hole and sinking fast" as any fule kno. Who breaks even on fruit machines ffs?
b) If her back's so bad that gambling's the only thing she can do then zooming around the CBB obstacle course probably wasn't a wise move.
c) If Jo was a proper gambler she would have known that going in as 5-1 fave would be a great opportunity for a mate on the outside to work on her behalf, lay her on the exchanges and make a fortune when her vile personality was revealed (hey, it worked for Big Mac a few series ago). Amateur.