This past week we had a breakthrough: Ruthie started taking a bottle without much (if any) fuss.
I started on Thursday, offering her a bottle during her mid-day feeding. Every time she got frustrated, I'd stop and cuddle her for a bit, then offer it to her again. Eventually she settled in and drank a full 3oz bottle of liquid, to my extreme delight!
The next day, I tried it again. This time, without any fuss whatsoever, 5oz disappeared almost immediately. So when Saturday came around, and I had to shoot a wedding in downtown Annapolis, I had no worries. Stephen offered her the bottle. Again: 5oz down the hatch, no muss, no fuss!
This is wonderful.