BB Fun with 43s: Brilliant or FPS river decision?

[Chipspin]

Regular loose 15 at the Oaks - avg of 5 or 6 players to a flop. Villain in this hand is a lady who clearly hasn't played a whole lot of poker, something like a 35/5/1.0.

PF: Lady raises UTG (this is a big hand... JJ+ and AQ+), 3 cold callers, SB calls, I call in the BB with 43s.

Flop: 652r.
check, I check, she checks (doh!), and checked around.

Turn: A, completing rainbow.
SB checks, I check, lady bets, all fold back to me and I raise, she calls.

River: A.
I check.