She is portrayed by Charity Wakefield.
Whilst having sex with Albert, Betty is asked by the scientist if she would move in with him. After the intercourse, Albert is still waiting for an answer, but Betty ignores the question and goes over his schedule, which includes being late to a lecture and having dinner with minister Rathenau. Albert asks again, and she reminds him of his wife Elsa, but Albert tells her that he doesn't agree with monogamy, stating that they are just rules set down by the church. He wonders why he can't love both Betty and Elsa, but Betty doesn't think he knows the slightest thing about people's feelings. The phone rings and Betty answers: it's Mileva Marić, who wants to speak with Albert, but he dismisses the call and leaves for his late lecture.