My nintendo ds lite the touch screen does not work

In some cases you can damage the screen with the pen clicking to hard also the pen is easy to break with muscle bones. You can try to buy a new one or you can use a light material such as a cotton swab. Replacing a pen with a new pen might be hard but use a light material or a fine material but nothing very sharp or sharp. Gentle just touch the screen.

If your stylus pen is not working on the touch screen there could be a couple of reasons. The screen could be heavily scratched , you could have a screen protector that is making it not function properly or your touch screen may have failed. I replace touch screens for $20.00. If you are a do it your selfer you could buy the touch screen off of eBay and you could find how to replace it on the internet. You would need a tri-wing screwdriver,a good set of eyes and patience. Hope this helps.

She seems to have broken the touch screen sensors which tell the game where the pen is. The only responsible way would be to get a new one.

The top surface of the lower ds screen can be replaced very cheaply. It's not the LCD screen, but the "digitizer" or touch screen.
You can get them on ebay for like $5:
http://shop.ebay.com/i.html?_nkw=ds+lite+digitizer&_armrs=1&_from=&_ipg=

If you don't have the know how to replace it yourself, maybe you can order the part and bring it to a repairman.

Here is Nintendo's guide to calibrating your touch screen, which should fix this problem.

DS fixing solution = NONE: Your DS is old and should be treated more gently. DSLITE: it has gotten to worn out. turn it off for 5-10 days at dry again.

double check that both cable/ribbons are connected properly to the motherboard, the small thin ribbon which curls over the top of the motherboard is the one which powers and reads the touch screen so double check this!!
if this is all in fine then im sorry to say your touch screen is broken and will need replacing!

i dont get you that much

aparently fitting a new touchscreen works, i have just ordered one from ebay, cost me a tenner

If the bottom screen was taken out then there would be a loosen or unplugged conductor, maybe only the touchscreen wire is out, you can open the system and plug it back to the jack. If the wire is broken then you need a new touchscreen (not the whole display, just the touch pad, like $9.99 + s&h).

Here is a guide to dismantle an original Nintendo DS: How to dismantle a Nintendo DS.

If yours is the NDS Lite, just find this video in youtube: "Disassembling Nintendo DS Lite"

Good Luck...