Erm... depends on the canon? She is in the Lee stuff. She's an American fighting with the French resistance, who has an affair with Steve though they never know each other's names.. Then Englehart in his infinite skeeviness made this whole plot about how she was so stricken by hearing about Steve being lost at sea that she fell into a coma for twenty years, only waking up when he revived. Then she sort of stalked him, and was mocked by everyone for going after a younger man. After Englehart #$#!ing finally left the title, she was back on more of an even keel, and ended up running the SHIELD staff that worked with the Avengers.

In a more modern retcon by Brubaker, she continued to fight through and after the war, and the coma was retconned out.