I actually browsed the novels tagged with zombie and apocalypse, but I can't find what I was looking for and have already forgotten most part of it. Herw it goes. MC is a zombie and had a baby or got pregnant with ML who is an ability user. MC has I think a fort or like a base of her own to which she manages and her family and friends knows she's a zombie while they are human. ML also has a base of his own. The baby is a zombie baby. Both MC and ML have an OP abilities. I think MC can do stealth or invisibility and teleporting. Also I'm not sure if this is just taken from other novel, since I have read quite a lot, but I think they're both from like the military and that they are not the only human- zombie couple there. Please help me find it~
It's been a long time since I read this, so I don't remember the details of this novel but perhaps it is Zombie Sister Strategy There is also The End Of The World’s Poisonous Mom And Monster Baby which I remember more of, but this novel is on several points different from your description. Here MC was pregnant from someone else, when she gets run over by car from his mistress and gives birth at the time apocalypse starts. Her son is half zombie.