I'm having a similar problem (just posted a thread also). My LO is 4 months old, ebf and occasionally takes the bottle. I keep a small supply in the freezer and sometimes will just pump some before I go out so my husband can feed her later. Last night and today she will not take it from either of the two bottles she liked previously OR some of the new ones we tried. We tried both thawed milk and fresh milk. Both husband and I tried. I don't know what happened! (Sorry to hijack your post Leigh!).
We're not going to try again for a couple days in case we've bottle-traumatized her in the last 24 hours, but if she rejects it again I might try what you've listed here optimistic1. Can I ask you, when you said you'd let her play with the bottle each day - was there always bm in it? So did you pump a little each day for the bottle? The idea of trying to nurse her and then slipping the bottle in somehow.... Seems like she might get the point easier. But I'm also worried that if I screw this up entirely - she could HATE the bottle experience and completely reject it...
I'm hoping to hear from other mommies too! Thanks for posting - I feel at least I'm not alone in this issue... Just seems so weird for it to happen all the sudden...
Good luck