4.5 BB/100 after 32,000 hands @ $0.5/$1.00 (is she any good?)

[ChessMan]

Hi,

My girlfriend currently has a winrate of 4.5BB/100 at 0.50/1.00 limit. She's feeling really confindent. I told her that if she was making money after 10,000 hands she should feel good, but we'd still have no idea how profitable she was. At what point do we know what her long term expectation is per 100 hands? I heard it was 100,000 hands.