It is good to stay alive to support your daughter.
Madeline has recently given birth and has been suffering from post-partum depression.
Madeline wants to end her suffering.
Madeline seeks therapy to deal with her depression.
Madeline drives her car into a tree.
Therapy brings Madeline out of depression, and she is able to watch her daughter grow up.
Madeline does not survive the crash, and her daughter grows up without a mother.