$1/$2 NL 6 max

I raise to $7 with [Kd] in EP. SB calls. I have less than 100 hands with him and hes at 26 / 18. Havent seen him do anything wierd or play any big pots.

He has $260 and I cover.

Pot $16 Flop [Tc][6h]. He check calls my $12 bet.
Pot $40 Turn . He check / calls my $31 bet.
Pot $102. River . He leads $51 and has $159 behind. He would check raise the turn if he had AJ or J9 , right?

Anyone think hes strong enough to call a raise?