I goofed. should i add a panel?

i am knitting my 6yo a ribbed and cabled pullover. i’ve already done the back piece twice. now, as i start the front piece, i discover that i did the back in the wrong size. :ick:

since it is made with a very chunky yarn. i’m wondering if i could successfully knit an extra panel of k2p2 ribbing for each side and mattress stitch it on each side to make up the diff.

input? should i just put on my big girl panties, deal with it, and frog the back and start over AGAIN? or should i cheat and add the panels.

what would you do?

I would probably frog it and reknit it, not because I think your idea is bad in any way, but just because I’d rather just knit than worry about making the panel the right size and then having to sew it on.