I wouldn't worry. Some LOs don't take to solids until they are a bit older and it's not like she's refusing everything as you say she takes a good breakfast and a few tastes at the other meals which is fine. It's also common for LOs to take more solids in the earlier part of the day, so a big breakfast and smaller lunch/dinner is quite common.
If you are concerned about the balance of foods because you prepare more variety for lunch/dinner you could offer those types of meals at breakfast instead of the traditional cereal type breakfast. She might be more willing to try different tastes (veggies etc) at that early meal.
Maybe try more like 60 mins after milk if that fits around nap times so she has a chance to be a bit more hungry.