I'm pretty sure I remember watching a Pokemon Chronicles episode where Flint is the gym leader and has to battle Brock's mum. I think she redecorates the gym to be a water one and Brock finds out, getting rather angry.
Also, I'm fairly sure his younger brother dreams of being the new gym leader, but has barely started being a trainer or something.
As far as the last chapter goes, I thought it was a little short, but otherwise I'm in enjoying this. Keep it up !