Hi ellaroo, this is probably way too late - I was on holiday - been back ages of course but this thread wasn't around when I gor back & I've only just discovered it. So sorry.
Anyway, the kiwi explorer. I really love mine but, and this is a big but, I can't use it any more really, as my kids are so close in age - 17 months, the same as your friend. The boys have been the same weight for ages, and the double system only works safely with 2 children of different weights. That said, that was just unlucky for me that the elder is small for his age and the younger is big for his age, so it tends to tip - not ideal. The company suggested strapping a weight to the footplate, but I haven't tried it.
Apart from this misfortune, the pushchair is great. Very very light & manoeverable, especially in comparison to a tandem which is very very hard work. It's so great on rough terain you hardly notice it, and I wouldn't consider anything without the swivel whell. It does tend to turn heads as it's design is unusual, some days I suppose I liked that but often I felt like taking photocopies of an info sheet out with me to hand to people who were blatantly gawping.
I found it very easy to collapse, but my dh didn't - I supsect just another job he preferred me to do so feigned ignorance.
I bought it as a double kit, which I suppose your friend would, so you're not actually buying the newborn bit seperately. I didn't find it really an issue about the newborn not being able to see, as most of the time ds slept as soon as he was put in it - a testimony to the fact he found it very comfy, and by the time he was 4 months he was just in the normal seat, which it quite reclined, so comfy for a baby too.
The customer service was good.
It's also useful in that you can just use it as a single, although to be honest, I always left the double seat on to pile all the bags & coats on, so that was very useful too. I did subsequently buy a tandem (I am a pushchair-holic) and it is a nightmare to push, especially with the slightest camber in the pavement. I couldn't manage with a side by side - there are just too many narrow places it would get extremely frustrating - find out the width of a side by side then see how many place & how many pavement you couldn't walk down!
Anyway, it probably is way too late - if this doesn't help you & your friend, at least let me know what she decided to do in the end!
btw, I got it shipped from nz, don't live in uk, but near lots of mountains that's no prob at al for fab buggy.