Hi, Venonima was in the book of girls mentionned has being pregnant. I went back to the castle no egg. I disable the light effect. No egg. And she is not pregnant, with no child? I gave her food for several days, mated etc...To see if the is eggs in Venomina's Cave disable the Light Effects.
You are saying you haven't seen the cutscene where the MC see a Spider Egg, try to take it, and then Venomina binds/capture the MC and he explains the Tower belongs to Erevi?
Did you feed her enough?
Normally you feed her a few times, mate a few times and she lay an Egg that trigger the scene I mentioned above.
After mating she should lay an egg in around a week.