L.C.
That sounds pretty normal. I would try to get her to eat some more fruits to start - she might find one she enjoys.
I would start every meal with something she is NOT familiar with - fruit - veggies - pasta...but nothing too out there at first. Start simple and then as she begins eating more progressively introduce more foods.
By starting the meal with something unfamiliar that way she won't fill up on bread. Or...stop keeping the other stuff around the house. Don't worry - she won't starve to death.
You could also try a yogurt drink, or pediasure (I think that's what it's called) I've seen some people use it for picky eaters.
Or take her grocery shopping and see if she wants to pick something out on her own...it might interest her.
You could also try making a game out of eating - there are so many options I would play off what interests her the most.
Mostly just keep introducing stuff and eventually she'll eat other things. I mean, have you ever seen an adult eat only bread, cheese and yogurt? Doubtful ;)
You may want to give her a gummy vitamin to supplement while she is being a little picky (not that it wouldn't hurt other times) - there are even gummy calcium and gummy omega3's (I tried those and they tasted fishy to me *yuck*).