1998 Church handbook 1 states that deceased women can be posthumously sealed to all deceased men to whom she was married.
Church Handbook of Instructions, Book 1: Stake Presidencies and Bishoprics (Salt Lake City: The Church of Jesus Christ of Latter-day Saints, 1998)
Sealing Policies
Sealing ordinances include covenants that can bind families together for eternity. These ordinances include (1) sealing of a husband and wife and (2) sealing of children to parents.
Stake presidents should contact the Office of the First Presidency or the temple in their temple district for guidance in special circumstances related to sealings that are not covered in these instructions.
Sealing of a Husband and Wife
Living Women
A living woman may be sealed to only one husband. If she is sealed to a husband and later divorced, she must receive a cancellation of that sealing from the First Presidency before she may be sealed to another man in her lifetime (see "Applying for a Cancellation of Sealing or a Sealing Clearance" on this page).
Deceased Women
A deceased woman may be sealed to all men to whom she was legally married during her life. However, if she was sealed to a husband during her life, all her husbands must be deceased before she can be sealed to a husband to whom she was not sealed during life.