I have no idea how to trigger this. It's been hundreds of days and she has yet to complain about not being able to nurse me and I can't give her any items whatsoever.
I've got 2 Purified LaBova's in my inventory but there's no option to give her anything. Just appearance, Talk, Her giving ME a present, break up, and release
You resisted addiction so that you have the 'Marble Resistant' perk and you chose to 'sleep with' in her talk menu but she still won't trigger the quest?
Have you collected bottles of milk from her after she joined your camp? That's the only other thing I can think of for interacting with her that might be required. I've triggered the quest in vanilla w/o ever milking her at Whitney's but I carried around a stack of 5 milks for the emergency healing effect or fatigue reduction after she joined my camp.