Need help fixing a hole in my finished blanket

Hi! I just finished knitting a blanket for my 3 year old son and I need to correct a mistake. There is a hole in the blanket that is driving me crazy. I apparently dropped a stitch and then on the next row I increased to make up for it and ended up with a big hole. Is there a way to fix it even though the blanket is finished?

My mom suggested using invisible thread and sewing two of the stitches together to cover the hole. (My mom’s not a knitter) so I wanted to check in the knitting community to see what is commonly done.

Thanks for any help and suggestions!

knittingly yours~

W/o seeing it you could probably take a length of matching yarn and weave it thru the hole (locking it in place and closing it) by working the tails into the WS of the adjacent sts.