Oh my, I'm sorry! I lurk here all the time, but sometimes I am ignorant of the rules. ^^;
What does CC mean? Also, thank you so much. I am going to do that now. I play the Sims daily and this glitch was driving me batty.
Edit: I have been digging through everything for quite some time now and I still can't find it. Very upsetting. Ugh.
I had the same experience last year with CC. I downloaded a sim from Exchange board and the sim came with CCs. I got a lot of baby monsters in Sunset Valley. The answer is quite simple.
The reason you got a kid monster is because that CC is actually more for young adult but it was also set to children's wear too. So how to solve this out is..
Open the launcher.
Go to the installed contents tab.
Scroll down and find the everyday clothing with tiny special mark like W..?
Most of the CCs come with very small 'w' mark on the thumbnail.
And they look a little bit different to the store items.
Especially, the items haven't set it's object or wears on launcher and they mostly make problems.
All the store contents are set as everyday wears,objects,hair...like this.
Then you will find it. Select it and uninstall it. Then finished.
Since that time, I don't use CC stuff any more.