Hi FrankA,
Sorry no-one has gotten back to you yet. I am no expert but the first thing I thought of (and please forgive me, but this has just happened so many times) is are you sure she is actually a she, and not a he? Perhaps you could post a picture of her so that we can just rule that out first. You would be surprised how many people I've heard of on this site, who are on the longest egg wait of their lives, lol. Again, I'm not trying to insinuate you don't know what you're talking about, but sometimes with our own birds it's harder to tell.
Ruling that out, a lack of laying hey...? Perhaps if she was at POL as Winter came in I could see that could stop her laying, although that being said my POL's started laying in the dead of Winter. I'm not heaps familiar with the BR's myself as I've never owned the breed. I'm no sure what the average age to start laying for them is, but 11 months sounds ....kind of late.
I do hope that in bumping this thread up it will bring in some answers for you. Sorry I can't be of more hep, but yes, a picture might be a good start.
All the best to you.
Krista.