I am soooooo very sorry. Please don't try to mend this with new fabric. New fabric with old will make a bad pucker or blow out the old. Find some older fabric (I have a vintage flour sack apron that might work) Do you know how to darn? Hand darn? Whip stich? An older floursack towel would work. The batting looks like cotton from here (my mother in law used to tell me stories of her mother using cotton for her quilts (not what we would call batting. If you are interested in the apron, I would be glad to send it to you......wouldn't match but it's old and it wouldn't be glaring. Others may also have older things that would work. Feel free to private message me if you want. I've done a lot of handing mending in my lifetime. If you can find older thread, so much the better.