@Dellenal, I've played this game for 385 hours so I'm not really excited about playing a new game for that long to see if it crashes haha.
Also, since only 12 are children, and infants are more like "objects," as someone on here pointed out, I don't know if that is the sole cause of the crashing. I think it's just a problem with the game in general.
I've taken this issue to the EA Sims Bug Report website now. I don't know that anyone here can help unfortunately.
If EA is going to make a game that allows me to collect lots of items and have lots of babies and play the same family forever then they are also responsible for making sure that I can do so without it crashing all of the time. This is on them.
I was at the point that I couldn't save ever, but now I lowered the gfx settings to the lowest possible and, before and after playing, I run anti-virus software, computer "cleaning" software, update and repair The Sims 4 via Origin and completely turn off my computer. That has made it so that I can now play and save ONCE. Then I have to do that all over again. If I don't, then it crashes on the second save.
Anyone else having the same problem may want to try that to be able to resume playing at least a little bit.
Anyways, despite all of this, I'm still playing the game and love The Sims! haha