I have had triplets in my present game followed by twins. The couple already had one child. The pregnancies all happened pretty close to each other. This is one fertile couple and only the first one was a 'try for baby'.
I use mods but this was not boosted by any fertility traits or me selecting the babies. I like to keep it a surprise for myself anyway.
So six toddlers all at once. Yikes.
https://i.imgur.com/k9uPQvh.jpg
Their names are pretty boring. My generations all start with the same letter so, as this save is just new, they all have A names.
So we have Alan, the eldest, the triplets are Andre, Andy and Alicia (Andy and Andre? Yes, pretty close to the same name but I wasn't thinking) and the twins are Alex and Amy.
It was pretty hectic for a while. My sims employed a butler and he was a lot of help along with Patchy who mended everything that broke and emptied the potties too sometimes. Yay for slave Patchy. Thankfully the twins have just grown up to child so the baby days are done in this household.