I am glad to hear all her tests have come back negative - that is truly awesome and you have done a great job so far in bf and introducing solids.

I am not sure if food is the issue, why the introduction of a bottle of formula - why not up protein rich foods and continue bf? Is this is what was suggested you do? - I am just a little confused that is all, not having a go.

BTW - your milk doesn't suck, your supply is what your bub needs - again it is food that is the culprit or like Kateo suggested earlier - perhaps an allergy/intolerance is stopping protein from being abosorbed? Don't confuse fat rich foods with protein - they are two different things. Protein is usually found in meat, fish, some dairy....