Who is Virginia from I Am Legend and what is their importance?

Virginia is Robert's wife who died of the vampire plague. Rather than have her thrown in the fiery pit with the other victims, Robert defies the health regulations and buries her in a crypt in a grassy area enclosed by a fence. Two days later, she returned from the dead and attacked Robert, so he had to kill her and bury her again. Despite these occurrences, Robert loves her dearly. He visits her crypt often and brings her flowers. He longs for the day when he can join her in death. In flashback scenes revealing conversations between her and Robert during her illness, Virginia, or "Verge," as he sometimes calls her, is revealed to be a devoted wife. Though ill, she offered to make his breakfast. Robert thinks of her often.