Definitely wash all your pumping parts between each session, and sterilize them once in a while with one of those microwavable sterilizing bags.
Does she protest when nursing also? It could be something you're eating (garlic, cabbage, etc.), but if she has no problem taking the same milk from the breast, it could be something about the collection and storage process. Or, she's just not crazy about taking your milk in a bottle and is being picky. Has she taken a bottle fine until now and this is something new?
Has the milk been frozen? Thawed milk does smell/taste different.
I would make sure you're following safe pumping and storage procedures, and see if you have changed your diet recently.
, married to dh for 22 years!
Homeschooling mom to ds17
our 3 1/2 year old potty princess