I’d give her the sweet stuff along with her meals. For example, we serve fruit with his meals, he’ll always eat the fruit first and then eat the pasta or the sausages. I feel like if they have a safe food on their plate, they might be more inclined to eventually try the other stuff
It's just a phase. Kids go through fussy phases I'd keep offering as normal and let her eat what she wants to eat
I have noticed that my boy’s appetite seems to have shrunk recently - he’s just not so hungry for meals so I wonder if it’s just a developmental thing. I’m trying to stick to just offering what I would usually and then he has milk at the start and end of each day so I know he’s at least had that plus whatever he has chosen to eat that day - like you say, always a banana and usually at least some form of bread (at the very least!). I think it will all even out in the end!