AT cbet sizing on QQ4rb 25nlFR

limper is 40-6 with 70% fold to cbet
sb is 20-14 straightforward high fold to cbet

sizing?
PokerStars No-Limit Hold'em, $0.25 BB (8 handed) - PokerStars Converter Tool from FlopTurnRiver.com

SB ($28.47)
BB ($24.30)
UTG ($36.54)
UTG+1 ($31.79)
MP1 ($38.47)
MP2 ($25)
CO ($13.08)
Hero (Button) ($25.25)

Preflop: Hero is Button with A, 10
4 folds, CO calls $0.25, Hero bets $1.10, SB calls $1, 1 fold, CO calls $0.85

Flop: ($3.55) 4, Q, Q (3 players)
SB checks, CO checks, Hero bets $1.90,

I think you need to bet quite small with the two queens out there, it may appear like you're inviting a call. I don't think a 2/3 bet would make them (both) believe you've hit the flop.
If you get cold called you can be very cautious in subsequent streets; as you're the last to act this is a great situation. If they both fold, you've risked the minimum.
You've bet under 2/3 pot but I think maybe even $1.20 could've scared them off?!

I think this sizing is goodish for any hand you'd bet here, maybe can even get away with smaller ($1.50ish).

i typically 1/2 pot these boards as default. dont mind slightly smaller as long as you are betting any 9+ on the turn

Less. Just be unbalanced as shit in this spot and then pass out from shock if anyone does anything about it or even realises.