She maybe cares more about giving her child a normal childhood in spite of logistical problems than she did about how the other parent would feel about it. It's my experience that most people don't care very much if they cause problems for others even when it doesn't personally inconvenience them very much (look around next time you're in public and count masks). How much more is this true when it's someone you presumably care a lot about and they're only a child for such a short time?