Does the second one sound OK and have the same meaning as the first one?
She was standing there with her eyes open.
She was standing there with her eyes opened.
For the straightforward meaning that I think you want, the first sentence is the usual form.
To have your "eyes opened" often means to be made aware of something, to be made to realise something.
"She had her eyes opened to the unfairness of life when she visited the slums".
not a teacher