It's too much. YOU should be freaking out. I understand being grateful about having her help and wanting to tread lightly so she doens't get offended or feel not appreciated. BUT she IS ABSOLUTELY overfeeding your child. And you should protect your child from that. Because the truth of the matter is that your baby DOES NOT need supplementation. And her wreckless mis-use of your milk if going to cause your child to get inferior nutrition. Don't stand for that. I agree that supplementation is not the end of the world. If it's NEEDED. But why corrupt feeding breastmilk exclusively if it's not needed? Formula puts your baby at risk. It just does. Often those risks are being weighed against other percieved risks like FTT or low supply. You DON'T have those problems. YoU HAVE plenty of milk and it's being squandered. Make smaller bottles. Make her feed less. Don't give your baby formula if you don't have to.