I think of that on this day, as I hug my own mother tightly and feel a twinge in my heart for my dear friend who's mother died 7 years ago today. It was rather sudden - a heart failure - and even though the family knew she had a bad heart, her premature departure from this world was not easy to accept. I'm lucky enough not to know this yet, but I would bet that the death of your mother is hard no matter what the circumstances.
And yet, as I write those words above - heart failure, bad heart, premature departure - I can't help but think that maybe this anniversary was also a first for her. My friend's mother might have had a weak heart by our physical standards, but she had a big & good heart by higher standards. Her heart may have failed her body, but perhaps it allowed her to be released from physical constraints to a place of higher consciousness and true freedom. Her premature departure from this world may have been right on time for her own journey into the first day of a new world for her.
I'd rather think of it that way on this quiet day, on her anniversary.