Standard or too aggressive?

[epi316]

My friend sent me this hand, he thought it was pretty standard, I thought he coulda slowed down a little. So you guys get to break the tie.
6-handed 1/2 limit. no specific reads on BB
Hero is on the Button with AA

Pre-flop:
UTG calls. 1 fold. CO calls. Hero raises to $2. 1 fold. BB re-raises to $3. UTG folds. CO calls. Hero re-raises to $4. BB calls. CO calls.

Flop (board: 5h Ts Qh):
BB bets $1. CO calls. Hero raises to $2. BB re-raises to $3. CO folds. Hero re-raises to $4. BB calls.

Turn (board: 5h Ts Qh 7c):
BB bets $2. Hero raises to $4. BB re-raises to $6. Hero re-raises to $8. BB calls.

River (board: 5h Ts Qh 7c Jc):
BB bets $2. Hero raises to $4. BB calls.