Technology has left me behind - presents for DDs 12 and 6!

[unlucky83]

Really struggling for 'big' presents for my DDs this year Feeling really out of my depth. Think technology has left me behind...
DD2 is 12 almost 13. Thinking I will get her a computer/tablet for Christmas. Something that works with WIFI (she doesn't have a mobile internet contract). And I don't want big ongoing costs...
One she can use for homework and looking at pop videos/playing games etc (thankfully not bothered about facebook yet)
Was thinking tablet then thought no keypad isn't good for typing on/homework -but then you can buy keypads for them - I think. But what about word processing etc? Would a netbook, or chromebook, even be better?
At the moment she uses DPs Netbook for homework (I use my laptop for work so it is off limits)
She has a pretty naff phone - which (if she can look after and not lose again!) will be upgraded for her birthday in Feb.
Could spend say up to £300 if absolutely necessary ...but would much much rather not! More like half that if poss! Any suggestions?
DD2 (6 - almost 7) has a leapad thing -and still loves playing with it but mentioned getting a Nintendo DS (DD1 has one)...thinking is it worth buying DSs now or is that relatively old technology? (and she could probably have DD1s at some point...)
My other option for her would be a better bike - hers is a heavy one, no gears etc but think that might be a better Birthday present ...
Budget for her is less - maybe £150 tops...
(And she doesn't know how much things cost so doesn't need an expensive main present to be fair.I could get her a sledge or a bean bag or something else 'big' and she'd be happy!)

(Should have said nothing Apple ...just don't like the ethos)

Laptop here for £179 or desktop for £149.

The new Nintendo 2ds here is the latest release, good value and will play the newest games just not in 3d.

Thanks but my fault - I realise my OP was really wordy ...and wasn't really clear ...
I don't really understand the differences between these things!!! And I want to get it right! So eg the Tesco Hudl thing is different to a kindle- more than an e-reader - but so is the kindle now I think - but might be wrong!!! But they run on OS other than Windows? Can you use a Hudl as an ereader?
Good eg of what I mean - I bought a basic smart phone a year or so ago...in a hurry cos my very basic phone had died. Wanted a smart phone (mainly to to check emails and do the odd web search/look at google maps). It was a mistake - it runs on Bada -so limited apps and support - I would have been better spending £20 more and getting an android one...(also my mobile broadband is rubbish -so slowwwww and expensive) - on the whole I just use it as a phone (and it isn't very good as one of those!) .
What I need is advice about the differences between these kind of things - maybe a link to an idiots guide to new technology????

And a DS still worth buying? (Not better than a cheap tablet??? - or wait for a year and get a tablet for her next year?)