Don't forget Les Halles for shopping/looking. It is expensive there, but looking is free. The sales in Paris begin around July 1, and you are to early for them, BUT there may be some "Reductions" in price you could look at. Soldes is my wife's favorite word in French. I agree on eat breakfast in, do decent lunch and small dinner or eat dinner in and then go out and see the sights in the evenings. We love to buy a rotisserie chicken (7.00 Euro or so) fresh salad makings - lettuce, carrots, broccoli, cucumber, tomatoes, onion, etc. (5-7 Euro), small cooked potatoes -in garlic and butter- (3.50 Euro) or rice, and a baguette (1-2 Euro) and make our own lunch or dinner. The great thing about this is you can get two meals from this plus, you can make chicken soup with the back, wings, and neck and get a third meal. 3 meals for 20 Euro is not a bad deal in my opinion. We have been renting the same studio in the 9th for about 11 years. It is fully furnished and has extras.
When buying food for breakfast cooking, bacon (US type) is called lardo and eggs can be pre-boiled, so be careful buying them. The french preserves, jams and jellies are wonderful. They use real sugar instead of beet sugar, corn sugar, etc. For lunch, we have a tradition of going to the Seine River and having a picnic. We buy apples, bananas, pears, or other fruit, a baguette, some good cheese, which abounds in France, potato chips (crisps) and a bottle of wine or soft drink and find a park bench on the Seine, and sit down, watch the people and the river and have lunch. We also do this in parks, etc. Makes for a cheap meal and great people watching.
Chinese and Indian restaurants are great places for lunch too. Look at the set menu on the window or on the board and see if you like anything. If so, go inside or just sit down an order it. Do not order from the menu. It will be twice as much. Also, as said above, order the house wine. Cheaper that way. In France, if you ask, they must give you a glass of tap water free. You can also order water, at 1 to 2 Euro a pint. We do free and are still alive.
If you order a hamburger at a cafe or restaurant, it will come rare and I do mean bloody rare. Wife did that last year and my wife was sick for two days. So, be forewarned. There are McDonalds, Kentucky Fried Chicken, American Pizza, :Burger King, etc. available . Your daughter might like do one of these just to remind herself of home. There are also English and French hamburger chains there and there food is comparable to those listed above. A lot of ordering in above is done by touch screen and payment by chip and pin credit card. There is usually one line to order face to face. This is what is coming to US if the wages of workers go to 15.00 per hour, so you will be ahead of the game.
How many museums do you plan to see in 7 days? The Louvre would take a week in itself. The others, over half a day each. You can get sensory overload really quick. So, look at the museums you wish to see, the shopping you wish to do and make sure the museum pass is a good deal.
We like to buy a carnet of 10 tickets at the metro then we will walk out and about, touring Paris all day. When we are tired, we use a ticket to get home. We use the bus, but I am handicapped and cannot use the Metro. You can do either. You can also use a ticket twice when traveling if you do a switch Meto to bus, etc. Might want to read up on that.
Galleries Lafayette and Printemps are great. Also look at Etam stores. Around each store are lots and lots of small boutiques which can be expensive, but again looking is free.
Enjoy your trip and plan to return.