After ♠A lead and sight of dummy I was quite certain my partner has taken 2NT as natural, so the question is if I could and/or should tell my LHO on the other side of the screen what has happened to avoid further damage.

The defence was: ♠A, ♥9-♥J-♥Q-♥2, ♠ to ♠Q, then ♠K and a diamond let me score 2♠ + 1♦ + 6♣,

Some of the damage in the defence self inflicted, but arguably some of it comes from the missinformation. Concretely opponents claimed that with correct information ♠AKQ + heart through for 1 down would be a normal defence, although 2 or even 3 down is not unthinkable if the play a club early and I squeeze dummy before missguessing diamonds.

When north was inquired about 2NT it was obvious she was not certain of the meaning, I think according to the rules this is as if she stated it without a doubt, but I am not sure.

I am mostly interested on knowing if I can alert the other side of the screen of likely missinformation, but as a bonus quesiton, how would you rule?

EDIT: Sorry I am a moron, I rotated the hand to put me in south, South and East are screenmates on this diagram.