Did she get any reflux/colic the last time she took the bottle? Just trying to work through possibilities.
I'd say keep going -- but very gently. What worked for me was repeating (silently!) to myself, eg, "Okay, if it doesn't work, that's fine, we'll try again later or maybe tomorrow, no problem".
Maybe have the bottle around when fun things are going on? So that it loses any bad associations.
xxx