That's actually a compliment to the character design.
“She’s a hot mess most of the time, she doesn’t give a shit what she looks like, she’s kind of stopped caring what people even think about her," Winslet said. "We made decisions creatively that this was a woman who looked at herself in the mirror when she brushed her teeth in the morning and would not look in the mirror again [all day]. That’s just who she is. That’s like most busy mothers I know—that’s like me. It really is.”
Read more at No Film School.