Irregular Time switch

I am seeking a time switch that can be switched on and it automatically switches off after a fixed period of time of between 30 to 60 minutes. My daughter attempts to read before sleeping every day but always falls asleep before she switches off the lights thereby leaving the lights on all night. I am seeking some form of timer that the lampshade can be switched in and which turns it off after a given perio of time. Can you help?
Thank you

Yes. I have a plug-in time switch which is quite cheap and effective. It allows me to plug in a double adapter (if I want to) and has a 24hour dial and 4 pins which allow you to set 2 on and 2 off settings in any 24 hour period. If you only want one setting-leave out one set of pins. Very basic - just how I like it! Cheap and easy to use. I have seen them in most DIY shops and stores, catalogues.

is it still working?

Yes, but the light hasn't gone out yet.

I think I'll take it back.