Neither! Get her Remington S8100 Wet to Straight Straighteners. They're wet to dry, which means they can be used whether her hair is wet or dry.
I think - but I might be wrong - that they're ionic, which means they condition the hair and make it less frizzy.
Also....
*Thermo-ceramic heat technology - I think this means that the ceramic is good for circulating and retaining heat.
*On/off switch - So you can keep them plugged in but off
*LED indicator light - flashes when it stays at whatever temperature is chosen for more than 30 secs-1 min. It keeps flashing constantly while the straighteners are on and it's at a temperature
*Temperature control - the temperature is adjustable, using a dial wheel on the side.
*3 metre cable - nice and long
*Heat protection bag - for carrying them around
*Vents in the top to allow steam to escape
N.B. If she uses them while her hair's wet, don't be alarmed to hear a 'sissing' noise, it's not her hair cooking!! I use mine instead of a hairdryer when I want straight hair and it's wet.
N.B.2. They're trickier to use if the hair is really wet and should NEVER be used in the bath or shower.
Hope this helps! My mum got mine for £24-30 in.... Superdrug, I think (She got them after taking back some own-brand wet to dry straighteners which stopped working after the first use).
The description is from Great Universal (http://www.greatuniversal.com/AgNet/product.aspx?sid=AQTF8DW0U6D11A4192MBB99WAX32VLD5&brand=GU&prod_id=203515&cm_mmc=FROOGLE-_-na-_-na-_-StraightenerWettoStraightStraighteners), but you can find out the cheapest ones using Froogle on Google.
If her hair is really long or thick, get her S8200 Wet to Straight Remington Straighteners (The paddles are wider than the S8100, which I use as I have short, fine hair)