50nl QQ should I bet the river?

[Das Budrick]

villain is unknown

is there value in a river bet here?

PokerStars No-Limit Hold'em, $0.50 BB (9 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

saw flop|<font color="#C00000">saw showdown</font>

UTG ($55.10)
UTG+1 ($29.50)
<font color="#C00000">Hero ($49.50)</font>
MP2 ($48.85)
MP3 ($55.15)
CO ($31.25)
Button ($11.20)
SB ($8.75)
<font color="#C00000">BB ($22.05)</font>

Preflop: Hero is MP1 with Q[img]/images/graemlins/club.gif[/img], Q[img]/images/graemlins/spade.gif[/img].
<font color="#666666">2 folds</font>, <font color="#CC3333">Hero raises to $2</font>, <font color="#666666">5 folds</font>, BB calls $1.50.

Flop: ($4.25) 9[img]/images/graemlins/diamond.gif[/img], J[img]/images/graemlins/spade.gif[/img], 7[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
BB checks, <font color="#CC3333">Hero bets $3</font>, BB calls $3.

Turn: ($10.25) T[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
BB checks, <font color="#CC3333">Hero bets $6</font>, BB calls $6.

River: ($22.25) J[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
BB checks, <font color="#CC3333">Hero bets $6.5</font>, BB calls $6.50.

Final Pot: $35.25

my river bet is half of villain's stack