Angel learns to answer ot Padme on Empire day, on that day she must pretend. She knows it's a day of grief for Vader, she knows that on that day more than any he just wants Padme, so that's who she'll be for the day. On Empire day they both pretend. Vader want Angel doesn't find out what he did to Padme on Empire Day. He doesn't know that Palpatine already told her. And yet with this knowledge, she gets ready each Empire day, places a pillow under her dress and ask Ani to feel the baby kick.