Silver Death

What, never heard of her? Typical. She has more kills than the Winter Solider. She was taken when she was 4 for her powers.
When she escaped she decided to keep her name. HYDRA thinks she is dead. They aren't looking for her.

When Clint crashes the quinjet in the field beside her yard, she allows them to stay in her house, no one recognizes her. No one, until Winter walks through the door, and sees a girl that he valued like a sister come up the stairs to greet him and his new team.

(This is set in a time and place where the Sokovia accords don't exist and Tony understood that Winter was not to blame for his parents death)