I agree with Rachel. At this age you still want your baby's main source of nutrition to be your milk. If you nurse first and then offer solids she will more likely fill up on breastmilk which is a complete whole food that no solids can replace in her diet yet. It may also be that you give her too much solids for her age. I think one teaspoon of whatever you offer her per meal is quite sufficient for a 7 month old.
Another thing is that babies her age don't self wean, it happens much later into toddlerhood. Instead, she may be going through the distracted phase where everything around is so much more fun than breast. Many babies between seven and eight months act like that, they even go on a nursing strike. To make her more interested in breast, nurse her in a darkened room without distraction like tv, other people. You may want to try to preserve one special toy she can hold while at the breast, some women use a nursing necklace which is made of sturdy colorful beads your baby can touch and play with while nursing.
Goodl luck!
