Thanks for the prompt reply. I don't know the egg color. However, I found the breed list that we got and we did have a single maren. From a Internet search I see that she is a maren.
I guess the proof will be in the egg color. She doesn't look quite right for a Marans to me, but a little too hefty for a bsl also. A Marans will have white/pink skin (bottoms of the feet is the best place to tell skin color) and lay darker brown eggs. A bsl will have yellow skin and lay regular soft brown eggs.