I think it's very sad and obviously there is a huge sense of loss but I don't think it's tragic. My perspective is in the last 6 months my own Mum has been diagnosed with inoperable cancer at age 56 - this came like a bolt from the blue, she hasn't been suffering with it from some time, simply had displayed some symptoms (initially thought to be minor) and after much investigation was told it was a rare form of cancer and that it can't be treated other than through palliative care. We don't think she has much longer than a year left although it's any body's guess and she is doing okay for the time being, every day is a blessing, and every milestone is an achievement - and she'll make her 57th birthday which last summer I didn't think she would.
It's all relative in that I wouldn't say my Mum's impending early death is tragic; in some ways I am grateful for the time we have had together (I'm late 20s) but I also feel a huge sense of unfairness in that she will never see me get married and never meet my children and despite working all her life and only recently retired will never get to enjoy her retirement and has spent (what little time she has had of it) in and out of hospital. As i don't have any children myself I think it is something I feel quite deeply because she is still my immediate family (although I moved out of the family home in my early 20s), there is no one more important to me than my parents as i don't have a spouse (although have a boyfriend of 18 months) or children. I also feel that this will be a life changing event for me, I can't see it not having an impact on how I live my life and it has all consumed my last few months - this may have been different had she lived well into her 80s and I was older when she passed. Somewhat obsessively I have worked out that I only need to live to 58 myself (which I hope I do) and my Mum has been in less than half my life which is something I find hard to deal with - how someone who has been there for me my entire life will just disappear and how if I live a long life myself I could spend 50 years without them and I worry that i'll forget her (I know i won't but have thought it in my darkest moments).
I think it's particularly hard because I feel like i am all alone in that people don't expect to lose parents when they are in their 20s so with one exception none of my friends can relate to me.
I don't want to diminish anyone's grief, grief is terrible regardless of someone's age and I dont believe the loss is any less but my overall feeling is that if someone dies at 82 there must be more blessings than there are things you feel cheated out of whereas if someone dies at 30 it's probably the reverse. I recognise that my situation is somewhere in the middle, and i try and focus on the blessings and the times we did have but sometimes the times we won't will win over my thoughts.
The one friend who knows my situation has lost both their parents within 5 years of each other - both in their 50s/early 60s and they have parentless at age 28. To them I feel lucky that I have one healthy parent and one with whom I hope to spend loving as much as possible but as much as I don't mean to offend I can't help but think that if my Mum lived to 82 I would feel so lucky. I know death of loved ones always come too soon but it would buy us another 26 years - which for now, feels like a very very long time (infact almost twice as long I have lived).
I do wish you all the best though, your Mum is your Mum and death is never easy.