For your DD - lego, marble run, hexbugs, magazine subscription, CD player, audio books, something she could play with in the car (like one of those fold down art sets that strap on the back of the front seat), shrinkies, playmobil (take a long house, camper van, swimming pool, pirate ship, school, hospital all have very good reviews - if you are planning on spending ££, you could take a theme like holidays and buy the camper van, swimming pool etc), a game like Guess Who or Connect 4 or Hungry Hippos
For your DS - something for the garden (lawnmower, sandpit, wheelbarrow), duplo (the numbers set and letters set are really good), happyland, supermarket trolley, hoover, easel, ride on, magnetic board and magnetic pieces like the djeco sets where you match up the heads, middles nd legs/tails of various animals like a misfots type game
For them both - DVDs? Take a look at the thread about presents that are not toys.