[Mossy Toes]

but was warned if I bring it she would bring some crazy formation that would table me turn 1.

Try "Up to 9 Riptides (3 squads of 3) who can fire twice (once per game if they don't move), reroll their Nova Charges, and get +1BS per prior Riptide that has shot at the squad they're shooting at."

I wouldn't say "I'm playing 150 Infantry," let her build her list, then pull out your tanks--that's flat out lying. I would say "build your list and show it to me before I show you which miniatures I've brought today." She cannot justifiably have a problem with that, so you should be in the clear as long as your minis aren't openly visible.

 

[Mossy Toes]

OK fine. I guess that suggestion was a little eye-for-an-eye, I just greatly dislike people who 'can't lose' at this game.

Way to be all normal and polite about it about it

An eye for an eye leaves the whole world blind. Except for the last guy, who would have one eye, and everyone knows that in the land of the blind the one-eyed man is king!

I just figure if you want to keep playing this person, maybe don't deliberately antagonize her--it's a fairly simple problem to address.