Encountered a strange repeatable problem cause by my own actions. Upon getting multiple Kimberly names as NPCs I replaced the names_f.txt list with a larger list of 1000 common female names. This worked for a while and I ended up witha lot more variation on new NPC names. Exactly what I wanted. I even later added 1000 male names just to round it off.
However, after a couple more changes to adding/enabling mods I started getting a CTD when the MC (male or female) would cl-max. Not every time, but when it did happen, thats what was going on. Could have two other NPC cl-max on each other and it would be fine. Or they could with me and it too would be fine. Sometimes the first time I did it wouldnt crash, but the second time it would. Frustraiting.
Since this trigger has nothing to do with picking a random name, I can only assume that there is some left over code in the game that looks up a name even without the Pregnancy mod enabled (yes, I had disabled all mods, it would still crash). Like maybe it is preselecting a name for a potential child and comparing it to the MC's first name to add a "JR" or "the II" to the name. Not sure why this would be done at conception rather than at birth, but whatever. It also would crash even if the MC was female or in a situation where no Pregnancy was possible. This added to the frustration.
I have not looked at the source of the code to see if a name lookup is indeed present at that time, but seems likely that there is one that is choking on the extra names added for no reason. Should note again that looking up names for newly encountered NPCs worked fine so it is probably not the same routine but a leftover one that has no discernable effect.
TL;DR: Moral of the story: Don't add more names to the name list file. Just deal with having multiple Kimberlies running around.