That is wonderful you were able to rescue her.
She will settle in soon
When I have come across a lot of gunk by the eye in a rescue dog, I have take a warm wet washcloth and just kept working at it until the gunk was removed. If it is a good size buildup, just have the wet washcloth and hold it between your fingers and work on pulling the gunk away from the eye. (Hope I explained that right - I could show you better than explaining, but I am nowhere near you)