Does She Have Any Chance On Living A Healthy, Normal Life?

My best friend is 15 years old. Female.
Two days ago, she was diagnosed with a stage 4 Non-Hodgkins Lymphoma. She has an indolent type. She starts treatment soon, not exactly sure when.
She’s devistated and is sure that she’s going to die. I cried for her..I want her to live a normal, healthy life as a teenager.
Does she have any chance of living a full life and getting through this? If so, what are the chances?