And honestly, whatever the reason - she's already showing you that she's not a reliable person to base your future on. You're young, and life is relatively easy, and yet she's doing this. She's not open to therapy or counseling to try to save things or examine why she's feeling the way she is. Let's say for example, that you reconcile. How do you think things will go 10 or 20 years from now when you have a child with a life-threatening illness, or a major financial problem, or she freaks out about aging and has a midlife crisis? Or you become ill or develop a chronic disease?
One of the great things about marriage is having a partnership where you help each other get through crises like these. And she's already showing you that when times are tough (in this case the loss in her family?) she pulls away, not together.
I'd say she's a poor bet for your future. If you DO reconcile, don't take her back without her getting a lot of therapy and both of you getting couples therapy - that's the biggest mistake I made with my ex. And getting some individual therapy for yourself right now might help you uncover the red flags you ignored in this relationship.
