Thanks all for advice. It's my first year breeding, and I'm still learning about time scales and such. But what do you mean keep pairing every few weeks? I was under the impression that I should pair them continuously, giving them a few days together, few days break/feed, and so on.
She is 1400+, although at the moment more like 1400; she lost around 35g or so over 3 months of fasting. I was planning to wait until normal breeding time in the fall, but I felt she was fasting because she was "in the mood" since none of her husbandry had changed. So I started pairing her with my YB male. While I hadn't directly observed a lock, there was definitely courting going on, and they may have locked over a day that I went away and left them together.