The lights of Chanukah dimmed for me this past year with the death of a beloved friend, Marilyn Katz. She died on the third day of the holiday, struck down by a highly virulent autoimmune disease. She had been ill at other times but always recovered, so her death came as a shock.

To be sure, death often arrives as a shock even when we know a person is terminally ill. The shock stems from the sudden realization that we will never see or speak to that person again. But in this case, I was shocked because Marilyn was such an optimist that it seemed impossible for death to overtake her. In fact, on the day before she died I had received an email from her assuring me that she was “doing better, due to antibiotics and the excellent care” she received in the hospital. And then she was gone.

I’ve read that email several times. Was she trying to spare me or did she truly believe she was on the mend? Probably both. Marilyn was that rare breed of person who saw the world and the people in it only in the most positive light. For her the glass was always half full. She took enormous pride in her children and grandchildren, but also in her friends. Rarely did a speck of jealousy mar the elation she felt in a friend’s happiness. There are people who — as the saying goes — are not happy with their own success unless they also see others fail. Marilyn was just the opposite. Her friends’ successes brought her as much pleasure as her own.

“Get yourself a friend,” the Talmud advises, and defines a friend as someone to eat, drink and share secrets with, including “the secrets of worldly things.” It holds up the friendship of David and Jonathan as ideal, but it might also have included that of Ruth and Naomi. Although mother-in-law and daughter-in-law, these women shared an unbreakable bond of love and trust. As Marilyn and I did.

So here is a conundrum: I am grieving for the loss of my friend, yet I don’t quite know how to mourn her. While Jewish tradition specifies rules and rituals for mourning a parent, a sibling, a spouse or a child, there are no rituals for mourning a friend, as powerful as that relationship might be. The week of sitting shiva for a parent or other relative, for example, helps bridge the terrible days that follow a death. It forces the mourner to turn outward a little, to focus on matters other than his or her own grief. And it allows the mourner to feel cared for, understood in some measure and freed to revisit painful memories within a safe environment. Saying Kaddish over the course of months or weeks also serves a purpose. The very act of reciting that prayer in a community of other mourners provides its own form of comfort and peace.

I did not sit shiva or say Kaddish for my friend Marilyn. The tradition did not require or expect it of me. Instead, I mourn her only by remembering and writing about her.

Writing meant a great deal to Marilyn. She had been a professor of English at the Cooperative College of Mount Vernon and SUNY-Purchase, where she helped students improve their writing. They adored her, as did those she served for nearly 20 years as dean of student life at Sarah Lawrence College. When she retired, she took up writing herself, and her short stories soon appeared in numerous journals. A collection of the stories, “A Few Small Stones,” will be published in March. Ironically, the title story, based on her family, tells of gatherings at their cemetery plot for funerals and unveilings. Who could have imagined that the latest gathering would be for her burial?

Another story rooted in her family revolves around an uncle, her father’s brother, who lived in Riga, Latvia, and came to visit America in 1939. When her father pleaded that with the growth of Nazism he must not return, he waved off concerns by speaking about the “good” Germans he knew. In real life Marilyn was haunted by the image of that uncle as he left on an ocean liner, the family waving goodbye until he disappeared from view — and would soon disappear from life itself.

Marilyn was a secular Jew, but she had a deep and passionate attachment to the Jewish people and Jewish memory. I didn’t get to sit shiva or say Kaddish for her. But as a new year unfolds, I celebrate her life, so filled with joy, and feel grateful to have been part of it. And maybe, after all, that’s as much ritual as I need to commemorate my friend.