Money for 2 in Paris, London

I was in same cities a little over a year ago with my daughters, and that's about what we spent for 2 of us. I was paranoid about spending any money at all at first, but I had enough.

Take this opp with your daughter to teach her how to travel. Don't just do everything for her because it's easier. She should carry her own day bag, luggage, moneybelt, spending money. Let her help figure out metro, tube, and bus routes. Look at maps, so she can orient herself. Talk about spending money priorites. Teach her how to assess safety in different situations. In a few years when she wants to go on a school trip, you'll feel much better about it. Should be a great trip. Have fun!

I think that amont is more than sufficient. The costliest items are liable to be meals so you can always save money there. You can size up the meal price situation once you are in Paris. Also avoid soft drinks like the plague as they are very costly.
Shopping is also a potentially dangerous area....
conversation on that topic is needed in advance!

Have a lovely trip.

I visit grocery stores and pick up snacks, cereal, fruit, yoghurt, wine, nuts, and chocolate. These can be eaten/enjoyed in your room or on picnics and can be used to augment a cafe/croissant breakfast at a neighborhood bar. You will save money by avoiding hotel breakfasts.