Villain has to have the jack here, maybe a weak suited ace. Push or fold this river? Calling seems wrong cos I am behind 100%. Also thoughts on the turn bet size?

Full Tilt No-Limit Hold'em, $0.25 BB (9 handed) Full-Tilt Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

MP1 ($19.25)
MP2 ($15.15)
MP3 ($8)
CO ($13.65)
Hero ($38.25)
SB ($10.85)
BB ($13)
UTG ($9.15)
UTG+1 ($17.70)

Preflop: Hero is Button with 9, 9.
3 folds, MP2 raises to $0.75, 2 folds, Hero calls $0.75, SB calls $0.65, BB calls $0.50.

Flop: ($3) A, J, A (4 players)
SB checks, BB checks, MP2 bets $0.25, Hero calls $0.25, SB folds, BB folds.

Turn: ($3.50) 9 (2 players)
MP2 bets $1.5, Hero raises to $6, MP2 calls $4.50.

River: ($15.50) J (2 players)
MP2 bets $2.25, Hero ??