tracyk, dd2 used to get bad nappy rash at nursery, and they did change regularly (probably far more vigilant than us ) . we thought it had to be the wipes they were using - at home we just used water and cotton wool. you could check what they use or even send your own preferred brand of wipes in.
will search out a photo of my dds in their preferred clothes, they look quite eclectic when they get going. my 4 year old really likes an old fashioned laura ashley red pinafore dress (too twee and nostalgic for me, she looks like a 1980's throwback), and my 5yo likes pirate stripey shirt, combats and then various strange additions such as sunhat in midwinter.