People with the same qualifications, skills and who put in the same amount of time and effort into the same job should be paid the same.

Sorry...I have a kid who is out sick and need to take the day off. Then I have soccer practice and can't make it to that huge presentation in the morning. Can that single lady work some extra hours to cover for me? I mean it's my family. As long as we're paid the same it's all okay!