That's a sad story, I'm sorry you lost such a dear friend.
"It's not to late" Doesn't have anything to do with her son.
She is refering to you, perhaps something you want to do? Taking responsiblty for something or someone??
Life is about lessons she made a mistake, she made two mistakes, taking her own life might have made the immediate problem go away, but it's still with her. That is what life is, making mistakes and learning from them.
If you come up with anything else or realize what "It's not to late" means to you, let me know.