I encountered viviane on day 121 and got all her dialogue, and then, without sleeping or otherwise leaving the old forest, spent two in game days fighting shit, and each night, getting her encounter, but even after more than 24 in game hours have passed, having her services and cait outfit button refuse to be unlocked. it was only after leaving the forest to sleep/level up at the frost hound that i was able to unlock her services at day 124