Splinter orders her to go.
It is one of those orders that is like steel wrapped in silk. It sounds like a request, but disobedience is unthinkable. She bites her lip against her protest, and nods. Splinter relaxes marginally, and she is still not quite skilled enough to be able to see what shape his fears are taking. Just that they are there, and that sending her away is the only relief he can imagine. She is given two weeks to pack and say goodbye (not coincidentally, the two weeks until spring), and then she is expected to spend all her time at April's, only seeing her brothers for practice and movie nights, where discipline and supervision can be assured. It is for her own protection, but it feels like she is being banished.
Mikey comes to her first, after the news gets out. She didn't want to be there when Splinter told her brothers, and his is the first fist to knock on her door after the announcement. She opens it a crack, and he's holding an origami turtle, the same orange as his mask. So you can remember me, he is thinking. She takes it and closes the door.
Don gives her a tassel the color of her own mask to hang on her naginata, for much the same reason.
Leonardo, displaying his usual insight but a surprising amount of delicacy, gives her a sketchbook. The first page is already marked with her name in Japanese done in elegant characters.
Raph avoids her until she is literally about to leave, and then punches her in the shoulder. The bruise won't last as long as the other gifts, but she will treasure it just as much.
April apologizes that she will have to sleep on the couch, and mentions maybe getting a couch bed, but after a moment or two she senses Venus' mood and leaves her alone.
She doesn't sleep that night.