rant.. I babysit a little 6 year old 3 times a week. I'm told when to get here. tonight I get here…

rant.. I babysit a little 6 year old 3 times a week. I'm told when to get here. tonight I get here at 5:45 when told. little girl still isn't here at 6:15 so I texted her mom and asked if she was running late or something. her mom replied it's not a priority to have her dripped off to you right on time. her little girl gets her at 6:30. Her old babysitter has been watching her these past 3 Saturdays when I've been told when to watch her and get told nevermind cause the mom had it off. her old babysitter dropped her off to me. I make barley 50.00 every 2 weeks for the 3 days I watch her. the old babysitter who has been watching her gets paid every saturday 60.00. this doesn't seem very fair to me. when she works 10:30 am to 11:30 pm and I work from 3:00pm to 10:30 Tuesday and Wednesday and Saturdays I work 9:00 am to 11:30.but if she's running late mom pays me from when the little gets there. does this seem fair to anyone else?