History? Well, here are a few ideas...
Take her to the palace for the changing of the guard.
A trip to the Royal Mews is good as well. Go to St. Paul's.
A trip to Greenwich can be good, she will get see to the Royal Observatory and stand on the meridian, etc.
One of the nice things about London are all the plays.
There seem to matinee's every where.
http://www.officiallondontheatre.co.uk/tkts/today I found the audiences at these to be a nice mix of Londoner's and very savvy theater goers.
You could also take her to see a Shakespearian play at the reconstructed Globe theater. Or just do a tour.
http://www.shakespeares-globe.org/I agree the food is not very good. However, it is worth stopping along the way for some fish and chips. Also a stop at a local pub can be a lot of fun.
Stop in at the Church of Saint Bartholomew the Great in the Smithfield area. It is the oldest church in London, having been built by Henry I, son of William the Conqueror.
Pete
