Grace Mayhew (1873–1894)
There are claims that James E. Talmage was sealed to Grace Mayhew posthumously, just as he had been to Zella Webb. Talmage does not confirm this in his journal but an entry dated November 22, 1894 alludes that Talmage was indeed sealed to someone posthumously, although he declines to write names or details of the ordinance (although noting that the details can be found in the temple record).
Sources
James E. Talmage Journals: October 27, 1894; November 22, 1894
Deseret Weekly 49, no. 20 (3 November 1894): 624, col. 2 (external link)