Thanks for your input.
Iphone 3GS - she wouldn't make use of all the features, so it's still too expensive.
Nokia E70 - also still too pricy.
Nokia 7280 - R U nuts? A lipstick-fashion-phone with a slider end and a Navi-Spinner in the place of a keypad? WTF... Nice idea, but no way.
Nokia 6810 could be it, but it's not available online anymore.
The new 100 looks ok too, but for 19€... what can you really expect?

Since she already knows the 2700 classic, I think I'll take her to a store and try out the Nokia C2-01, 100 and alike and see how she likes them. It's hard to decide without having them in hands and actually using them.