AJ's girlfriend bought/gave me a "scratch" lottery ticket. ANd low and behold, I won $50... Question is should I give her the money or half or not?

I haven't had $50 in my pocket for years. ... SO can I keep it all or do I have to be nice and share.. I'm asking cuz I don't wanna share .. WOndering what other folks would do...

I didn't ask for the ticket.. SHe just out of the blue handed me three scratch and 2 power ball tickets.. Now If I should win the $248 Million on the power balls, I would of course have no problem sharing it with her.. But then winning the jackpot is only dreaming so that prob doesn't count.. Guess I prob should give her half of the $50 and do it with a smile/