An Indonesian woman who lost her fiance in last month's Lion Air plane crash near Jakarta went ahead with their planned wedding alone, to fulfil his last wish.

Hospital worker Intan Syari, 26, and medical doctor Rio Nanda Pratama had hired an event organiser named "Adiela" and picked Nov 11 as their wedding day.

Dr Rio, 26, was among the 189 people on board Lion Air Flight JT610 that crashed after take-off from Jakarta on Oct 29. He was returning home from a conference there.

It was Indonesia's worst aviation disaster since a Garuda Indonesia plane crashed in Medan in 1997, killing all 234 people on board.

Ms Intan wrote on her Instagram account @intansyariii that, before leaving for Jakarta to attend the conference, Dr Rio jokingly told her: "If I don't return by Nov 11, go ahead wear your wedding dress that I chose for you, wear beautiful make-up, ask for a fresh white rose from Ms Sheila (wedding organiser), and take good photos. Then send the photos to me."

Photos of Ms Intan wearing a white wedding dress and holding white roses went viral on social media in Indonesia. One had Ms Intan showing her wedding ring.

"There is sadness that I cannot describe, but I have to smile for you. I shall not mourn. I have to stay strong like you always told me," Ms Intan added.

She also said in another posting with a picture of her and a sister of Dr Rio: "Although you are not beside me, your sister was with me to fulfil your most beautiful last wish. I know you are happy up there."

Ms Intan disclosed her age and her would-be husband's to The Straits Times while confirming her posting on Instagram.

She told The Straits Times that her late fiance was a medical doctor at Bakti Timah hospital, in Pangkal Pinang, where she works in the finance department.

"He always reminded me... that in the world, nothing is eternal," Ms Intan said.