Holbrook recounts Johnson dying in the Smith home in 1833.
Joseph Holbrook autobiography and journal, circa 1860-1871, 28-29, MS 5004, Church History Library
March 18, 1833
. . . .
Mary Johnson, a sister of Luke and Lyman Johnson, died at the Prophet Joseph Smith, Jr.’s home, age about 15 years, which caused much gloominess at the prophet’s house.
Mary Johnson died on March 30, 1833. Pictures of her tombstone can be seen here: https://ancestors.familysearch.org/en/LLSZ-BRM/mary-beal-johnson-1818-1833