its simple apply situation 1 to your dad and situation 2 to your mom, problem solved. But on a serious note...
1. I have not seen too many people getting kicked out for no reason, there has to be more to the stpry. Does she gets home late? smokes? drinks? what about her grades? is she in college? does she work? going out with too many guys?
And of ofcause, its not really your problem, sorry if its going to sound rude, but stick your nose to your oen business and let herself deal with it.
2. So what was the reason for not letting anyone know? Not a smart move, and again its not on your shoulders in anyway.
3. Do you work? I mean, even if you are in high school, you can manage to help your parents with at least $1k a month. If your father can not be a responsible head of the family, take his place. Read on how you can save bunch of money on bills online, fatwallet.com forum would be a good place to start. Look for coupons when buy things. I'm pretty sure there are many things could be done in your situation.