Meat, in and of itself, isn't something that you must eat any particular amount of. Many people are quite successful vegetarians and vegans, even as children, and on the other side of things, well, many children have meat-centric meals at least as much as you describe with no ill effects.
The important consideration is the diet as a whole, and what effect meat has on that. The kind of meat, in particular, matters; eating skinless chicken breasts you're eating nearly entirely protein, zero fat or close to it. Eating a breakfast (pork) sausage on the other hand is a huge amount of fat, mostly saturated.
Children's needs aren't all that different from adult's needs, except that there are some things that may benefit them in their development (although most things like that are speculative still). Fish (particularly cold water fish) for example is supposed to help with brain development because of some of the fats in it. In general, though, ensuring your child is active and eating a normal amount of calories with a balance of protein, fat (some, not none!), and vitamins is what is important. If she chooses (or you choose for her) to get that protein through meat, then that's fine, so long as it doesn't mean she's eating a huge amount of fat along with it.
If you're looking for some specific guidelines to make this easier, look around; there are many good references out there. Some examples:
The Mayo Clinic Guidelines are a good place to start. For a girl at seven, she should be eating 1200-1800 calories, with 3-5 ounces (85-140g) protein-containing foods per day.
HealthyChildren.org's guidelines recommend 3-4 ounces (85-115g) of meat and beans per day.
The USDA's Choose My Plate site recommends for a 6-8 year old eating 1400 calories per day, 4 ounces of protein foods as well. They also recommend at most 4 ounces of oils (=fats) per day (115g).