i just got switched from nights to days. i worked 7pm-5am. it's definatly weird how when you get no sleep and you work nights, it seems impossible to make it through the night. on days, it's easy as hell.
i work in a liquor warehouse. on the night crew, i'd be throwing 50-60lb cases all night. (and i only weigh 130, so they're almost half my weight!) but if i didn't sleep enough, i'd be doggin' it all night long. i'd be the hold up, when normally i was one of the quickest workers there. most of it is mental strength.
on days, all i do is inventory now. i guess that's what you get when you bust your ass for over a year straight. needless to say, the night crew now hates me for my promotion. i guess they should have worked harder.
as for your mom waking you- that sucks ass. i'd be pissed too. however, i'm a very family oriented person. if anyone in my family needs me, you can bet i'll be there in a heartbeat. there were days when i got 1 hour of sleep, and worked 15+ hours/ day. i was delerious with lack of sleep. 75-80hr weeks = lots and lots of money, but kindof ruins your weekend.
as for the sister- sit down and talk with her. ask her if there's anything you can do. even if she says no, at least she has the option. options are always good. and it'll make her feel more loved by her family, and more likely to let go of her ex. trust me, you'll be tired, but in the long run, it's the right thing to do.
-shaeff