Lego Creator 3 in 1 sets are good. Just bought two for my friends children aged 8 and 11. 31063 and 31068 £16 and £17 respectively. Arrived yesterday from Amazon, substantial sets for the price bearing in mind how much Lego is. 17 year old perhaps Soap and Glory or Jack Wills type gift set from Boots.
dressing gown, fluffy socks, boot slippers, cute hat, gloves, onesies, make-up bag. For all ages, but the 17 y/o will obviously need something more sophisticated, and might prefer to see a Topshop label if you can manage it. Jewellery from Topshop - she can exchange it if it isn't her style (not pierced earrings).
Also good; stationery (Paperchase for 17 y/o, Smiggle or Tiger for the others). Fairy lights.