i pad or laptop for 15 yr old

Robisere

How about a Netbook for less than £200?

Try this:
http://www.amazon.co.uk/Acer-Aspire-D270-10-1-Netbook/dp/B007I3PBAG/ref=sr_1_2?s=computers&ie=UTF8&qid=1355333206&sr=1-2

I know, long address, but there are others on the site. I have just bought this for my 16 year old G-Daughter, all she needs is Facebook, emails, school work, usual teen girl stuff (mainly Justin Bieber).

Your daughter may have more requirements, but anything above that may be done on the PC. Are your computers networked?

Lifeforms

If she's putting towards it, get her what she wants, not what you think she should get. Of course a laptop is far better, but it's not an ipad, and of course she'll be dictated by fashion and peer pressure, but they can be incredibly useful, as well as fun. She'll need to either use your card on the apple store, or more wisely, save up for gift cards to buy apps. Make sure she's very aware that there are free ones, but also costing one, and that she'd be responsible for buying them out of her money.
As with anything, always monitor what she is doing on it, but you can do somewhat parental locking (iirc) on the ipad mini, spotted it on mine, but not looked at it.

If internet is ever a problem, turn it off, or turn off wireless, and have the desktop wired in. No wireless, and no internet on the ipad.

Yes they're expensive, but if she's collecting cash for xmas, and then finding some herself, then it should be her choice what she wants. You could suggest an itouch instead, but it's not quite the same as a bigger one (ipad mini).

Also if whomever it was who thinks they're quiet, you've not heard someone typing on it with long nails! I Click Clack on mine