It is a tricy situation isn't it? I agree with the other ladies about the posibility of part time/ casual. I have only recently returned to work (2x 5 hour shifts a week) and i am starting to wonder if i should have when it comes to organising kids etc.... but for my adult time i needed to do it. The other alternative is to set out to do your given shifts and if you are unable to, maybe cut back on hours then.

Good luck.