|Title||Lady of the Crossing|
|Born||In ~217–254 AC|
|Died||In 269–278 AC|
|Spouse||Lord Walder Frey|
Alyssa was married to Walder Frey after his third wife, Lady Amarei Crakehall, died in 264 AC. Alyssa and Walder had five children together: Lothar, Ser Jammos, Ser Whalen, Morya and Tyta Frey.
A Dance with Dragons
Lord Tytos Blackwood mentioned to Ser Jaime Lannister that his son Lucas was slain at the Red Wedding, even though Lord Walder's fourth wife had been a Blackwood. He notes that kinship counts for nothing at the Twins, no more then guest right.
It is unknown how Alyssa is related to the other known Blackwoods.