Nice spot to OB? should we have chosen a smaller or bigger size?

Hero (BB): 66.53 BB
BTN: 62.1 BB (VPIP: 0.00, PFR: 0.00, 3Bet Preflop: 0.00, Hands: 1)

Pre Flop: (pot: 2.57 BB) Hero has Td Qd
fold, fold, fold, fold, fold, BTN raises to 2.4 BB, fold, Hero calls 1.4 BB

Flop : (6.37 BB, 2 players) 4s 2s 6d
Hero checks, BTN bets 3.19 BB, Hero calls 3.19 BB

Turn : (12.74 BB, 2 players) 5c
Hero checks, BTN checks

River : (12.74 BB, 2 players) 4d
Hero bets 15.01 BB