Please help

WOW! I have never had that happen and I am sorry for your sim. I can't offer you a solution but if you were doing the !00 baby challenge, your sim would win! I hope someone here can help you as I know the frustration. You could and I know this is crazy, cheat age a few up to take care of the others. It would be a real challenge to play that many and I wasn't aware the game would let you have that many in a house so crazy. Hope things work out

kupofhighc​  If you still need help, this is called the infinite birth loop, among other things, and the fix is an NRaas mod that can't be discussed on this forum.  It starts with a W and can be downloaded from the NRaas site along with all the others.

If you don't want to use mods, there's not much you can do other than revert to a previous save, which doesn't always work.

You could delete the doors, set the house on fire and make them all die while you go and make a cup of tea. Maybe even go to the shops, come back later.

Eleven babies to care for at once would be scary 😲but congrats to your sim for breaking the record for highest number of babies in a multiple birth! 😅 Wonder if restoring to a save before she gave birth and sending her to hospital to have the baby there would maybe help as its a rabbit hole and so no animation or anything, heard of this glitch but never experienced it so not sure...😕