She sometimes wanders off by herself to pick apples or go fishing in the forest. And also sometimes visits the milk farm, if you ever brought her there.
She'll come back eventually on her own, or you can even go find her and help her.
You need to get Alissa to interrupt you and Cassie 3 times! The one most people miss is having to annoy Cassie (make her change clothes a lot. She can't be pregnant for this.)
are you in the middle of inducting alisa? by triggering I think 3 of her encounters, cassie instigates you doing something about it so it's no longer a problem. otherwise... maybe if you have an old save?
