Have you tried many different nipples? Also she may do what a lot of BF babies do....wait for mommy. My girls eat very little from my DH and wait for me to get home from work. They then eat non stop. Many babies do this. Babies are smart and she definitely wont starve. Try posting this on the BF board too. Some of those ladies might have some ideas too :).

How long have you had her? My son would not take a bottle at all at home even though we worked on it nearly every day from 6 weeks on. The first full week that he was with the sitter he wouldn't eat all day and then would nurse as soon as he saw me. It got better after a week or so and now at 6 months he doesn't have a problem taking a bottle from anyone (including me!)

Just to confirm - you are giving her breast milk bottles right? It would be more difficult to get her to take a formula bottle.

Some other tips - try 'cup' feeding. Let her smell/taste the milk and then let her drink it out of the bottle like a cup. Try several different nipples designed specifically for BF babies. Put a little milk on the outside of the nipple so that she can taste it when the nipple goes in her mouth. Try feeding her before she is 'starving' - at the first signs of hunger. Have mom leave a shirt behind and drape that over you when feeding her so that she smells her mother. Try a position different than what she is used to when nursing - (ie, not the traditional cradle hold) my son takes a bottle best when sitting up in the sitter's lap a position that he now will not nurse in.