fledgling

Hello, folks! Can you give me a hand?

I'm looking for a painting I saw probably ten years ago. I believe it's an oil painting. The time period looks rather old, seventeen hundreds maybe? I'm not certain. It could honestly be quite modern.
It was about five feet tall and three feet wide--more or less life-size. There was a teenaged girl standing behind a mostly-open door. She may have on a green dress. She's holding a dagger pointed at her chest.

Could you give me suggestions on how to find this? It's gorgeous, and I've been thinking of it for a decade now! I'd be really excited if anybody's seen or heard of this.

Thank you so much.