I think that it should still be in the game, but you're totally right that it's a little more rare now! The trait that was previously Witchling has been divided and adjusted a little bit, so now there's a slightly different path to getting a Witch Mom.
If you have both the traits 'Loving Parent' and 'Mother', then there may be a bug in the code though! I thought I may have seen that scenario happen on a stream, but I wasn't able to recreate it so I wasn't sure 🤔