I've heard that typically they will lock until ovulation. So if she was locking in January she probability hadn't ovulated, I'd let her shed out n then pair them. If after a few attempts and no lock then I'd say she possibly ovy'd and this could be your post ovy shed. But truthfully I think all that stuff is hit or miss. My best suggestion is to pair her til she refuses to lock, feed til she stops eating n just wait to see some eggs. Don't stress, if she isn't going to lay then there's nothing you can do anyways.