It needs to be square when you send it to your longarmer!
If it isn't square, it doesn't roll up on the take up roller evenly, and the problem will just get worse as it's quilted along.
Of course longarmers work "magic" with unsquare quilts a LOT, but do both of you a favor and get it as square as possible before sending it, she'll do a much nicer job of the quilting that way.