I made a quilt with kimono ladies and happened to wash the fat qtrs first. not enough fabric to do that!

somekits have a lot of extra , some minimal, depends on what kit you have.

You could mend the tear with a fusible knit interfacing.

I'm currently sewing my first kit from Connecting Threads and it looks like they gave me almost double what I need, but then it IS just a 14" square and they included a fat quarter for each of the colors.

If you tell us the name of the kit, maybe we can find the fabric you are missing.

Contact the company. I cut a strip wrong from a kit and couldn't finish the quilt. I don't know why I waited but it was a couple years later and I was going to the quilt show in Chicago (where I had bought the kit) and took the strip with me. The vendor was there again so I stopped and told her I needed a quarter of a yard of this material and showed her the strip. She asked if it was from one of their kits and when I said yes she told any time that happens, mail the strip and they will sent a matching replacement. It is cheaper than putting extra fabric in each kit. Granted the quilt had 25 or 30 fabrics so I understood that. Got the piece I needed the following week in the mail.