sim only has boys

@zkhuey, like @HufflepuffHayley  stated, it is just random unless you do something like listen to certain music or eat certain foods like you mentioned. 😇 I have not heard of this being a bug, but I could be wrong.  One of my large families has all girls out of 5 kids, but most have a mix.  If I were you, I would do a test house -- make a new Save Game, make a mom & dad, place them in a house and keep trying for babies.  (you can skip past infant stage by ageing them up, and then age them up again with cake if you don't want to take care of so many toddlers during the test). Or since this is just a test, you can move in another adult or 2 and when the babies become toddlers you can have the other adults move out with the toddlers so you can focus on testing for gender percentages.🤓  That way you can have more children to give you a more accurate outcome to your test. You can also go into Game Options and give that household a short life-span if you want to speed things up, but this is not necessary. 😉  

The only other thing I can think of is that if you play with Mods or Custom Content (CC) , then there could be some Mod/CC that is causing all boys, in which case you would have to temporarily remove your Mods folder to your desktop and test you game without it.  🤨  But you all boy-child family is probably just random! 😉

Please tell us what you find out! 🤔

Happy Simming! 🥳