Scaredy Cat? Help needed!

Hey Everyone. So this is izzy. The tabby, Midnight is the black one laying behind her! They are best friends. This week my finances cousin moved his bed and dresser out of the room we are turning into our nursery and we set up the crib the next day. That day we left the window open to our second floor apartment, izzy loves window sills and fell out that same one as a kitten. She was perfectly fine just scared. Didn't stop her from continuing in window sills. The window screen isn't in the second bedroom window, I plan on replacing it next week. Izzy and midnight were in the room with my fiancé and I. Something happen, not exactly sure what but we assume izzy almost fell out the window. After this incident she was obviously scared, not hurt just scared, but now it's been 3 days of her refusing to move around the house and being really skiddish. I've tried working with her with treats and we moved her food dish to a place she will go. Anything else I might be able to try to calm her down a bit? I know it will take time but I love these two and hate seeing her like this.