50NL KK facing river b3bai

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PokerStars No-Limit Hold'em, $0.50 BB (6 handed) pokerhand.org hand converter

MP ($56)
Hero ($51.30)
Button ($25.60)
SB ($58.20)
BB ($21.75)
UTG ($9.30)

Preflop: Hero is CO with K[img]/images/graemlins/spade.gif[/img], K[img]/images/graemlins/club.gif[/img].
<font color="#666666">1 fold</font>, MP calls $0.50, <font color="#CC3333">Hero raises to $2.5</font>, <font color="#666666">3 folds</font>, MP calls $2.

Flop: ($5.75) Q[img]/images/graemlins/heart.gif[/img], J[img]/images/graemlins/diamond.gif[/img], 5[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
MP checks, <font color="#CC3333">Hero bets $4</font>, MP calls $4.

Turn: ($13.75) 4[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
MP checks, Hero checks.

River: ($13.75) J[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">MP bets $9</font>, <font color="#CC3333">Hero raises to $29</font>, <font color="#CC3333">MP raises to $49.5</font>, Hero ???

villian was a weakish TAG and my image is LAG. I usually bet the turn but tried something different this time. I'm looking for feedback on my raising on the river and what I should do once villian shoves.