They should appeal the decision. Mind you, had this not been brought up or asked about in the right way to the right person, the military would not have told the family that they could appeal the decision.
Women don't belong on ships or in combat. They are not physically able carry others out or have the muscle to secure passage ways, etc. And, yes, they do get pregnant, get sent to shore duty and some fellow has to come out and take her place. Not, fair at all.