Abel Chennouf was killed in a series of killings by Mohamed Merah last week. Mohamed, who claimed to be an al-Qaida member, shot and killed seven people -- three soldiers, three Jewish children and a trainee rabbi -- in and around Toulouse between March 11 and 19 during three separate incidents, CNN reported.
Merah was shot and killed by France's elite RAID police squad after a 32-hour standoff in his apartment Thursday.
Caroline Monet, 21, said she hopes to marry the late Chennouf within a few weeks.
"I've already had it done twice, for policemen's girlfriends. It's a really moving ceremony, with an empty chair representing the dead spouse," her lawyer, Gilbert Collard, told Britain's The Independent Sunday.
Collard said President Nicolas Sarkozy's office has already indicated he would give approval for the ceremony.