Hi Ben,
First of all welcome to a place nobody really wants to be..My son is your age also so I know how your mom feels..She doesnt want you and your other siblings to worry about her...She really wants your family to continue to be normal like it was before you found out about the cancer..I dont have cancer but I am a mom and I know thats how I would want it..
As far as how your mom will feel everyone is different, some continue to work, while some have a more difficult time..Chemo has a come along way since the earlier days..
Tell your mom dont give up hope, there are many that are beating this monster that are in the late stages of LC, many on this board who are LIVING proof as you will soon see, watch as the responses pour in.