You can't use the fact that she returned some of the money as an indication of cheating, because it doesn't make sense to ever return the money, even if you were cheating.
It does make sense if you have a guilty conscious and think you just got caught. Giving it back eliminates the financial gain. Now there’s much less of a crime since there was no profit.
There’s also motivation to give someone money if you were honest, like trying to make them happy or go away, but it’s an expensive way to accomplish that and probably less common.
The hand is relevant on the calling side. Poker doesn't work on the principle of "I called your bluff and so I win!". If you call a bluff with a worse hand, you still lose the pot.
If you call an "all in", you will have to beat the hand of your opponent. So the fact that she had a TERRIBLE hand is definitely relevant here. No sane person, let alone a PRO player, would call an all in with such an horrible hand as she had, since even if he was bluffing, a simple 22 pair would beat her nothing hand. She was cheating 100%, the fact that she returned the money and didn't call the theft of another 15k, from the guy that probably was her accomplice, is just the icing on the cake, it's the "ok whatever you guys want, just leave me alone and let's not talk about it anymore".