@eterhniteDo you use MCCC mod? Because if you use it, you have apparently not selected the option "skip played family"
If you do not use it, the only answer is that you have not actually marked these families as "played". There are two options, one strongly green symbol of "played" family and the other option is pale green - meaning, that this family is introduces by you to game but it is not "played" These families are managed by the game.
Unwanted romances unfortunately happen in played families but children - without mod - never.
I don't work for EA
