Clothes for skinny bottoms/short legs!!!!!!!

[Janus]

Following on from the thread about big bottoms!!, my daughter is incredibly small for her age (2.3 yrs) and so it is so hard to find trousers to fit her. At the moment I buy for 18-24 months but they are all big around the bottom/waist to allow for nappies and she doesn't even fit these properly (she is nearly out of nappies and if I put knickers on instead they can, literally, fall off her bum). They are also a bit long but I could take these up I suppose.
Hennes is a nightmare, lovely clothes but ridiculously big but I get all her tops there. Next are usually big, haven't tried Gap for ages and do buy from Boden as they have great elasticated waists but they're not cheap so looking for a cheaper alternative.
Any ideas? Thanks.
PS She'll be grateful when she's 18 I suppose!