Nobody has pocket aces. Pocket aces would have raised the flop bet.

Button's preflop raise doesn't mean all that much, he knows UTG will have limped in with any 2 cards, so he could have been trying to get the blinds to fold with a large range of cards. He could have A9, pocket 4's, pocket 2's, or the one hand you're worried about, pocket 9's.

I 3bet the river.