I am sure you know that she really doesn't technically need more than breast milk her first year. You said that you know your daughter needs more than just breast. How? Just curious.
The fact that your daughter did eat food just fine, especially bananas and is now refusing could be just "a thing" she is going through. That sounds frustrating. So sorry!!
Marianne has a good point. I heard that as well.
I am still nursing my 9 month old. I first tried giving him rice cereal, bananas, and some veges. He completely refused. I tried and tried but no luck. He just wanted to be nursed and I nursed ALL THE TIME! Seriously, all the time. He is one hungry lil' man. I then tried a few months later at 8 months and he was more willing. Not all the time, though. One day, he will seem like he loves green beans and the next day he turns his nose at them.
My first child, Nathan, was much easier with food. I only nursed him for 10 weeks. I heard that may have something to do with it.
I guess I would try not to stress over it. If she is still nursing just fine then it is likely she is getting enough. My milk supply seemed a little off at times and I was very concerned. The doctor stated that as long as he seemed to be gaining weight and had wet diapers, then we didn't have to be concerned.
Hey, I actually like the baby cereal!! Strange - I know.
Good luck