Kate and her husband moved from the flat they shared with two French Canadian architects out to their own little home in suburban SW 14 - the first of many life changes they will make now they've become parents.
Her husband has a great job in the city and Kate was doing well in her job in public relations, but she has wanted a baby for a while and was happy to swap her job as a consultant for one as a mum.
They married very young - before Kate graduated from law school - and a family was always on the cards.
Kate has always done things the right way around - unlike her mother. From a very young age, she wanted to be a wife and to have children and a career was secondary.
Perhaps that's because her own upbringing was unconventional. She has always been Saffy to my Edina. When Absolutely Fabulous first screened, friends took great delight in pointing out the similarities.
It seems if you want to raise a conservative, sensible young woman you have to be as nutty as possible yourself.
I would have loved more children but that wasn't to be and since Kate was married I've been looking forward to being a grandmother.
My own mum and dad were invaluable when I was raising Kate and absolutely relished their roles. Now that day has come, I hope I can do a good job.
The young parents have already booked me for babysitting on Monday night. Right, said Kate, you arrive Sunday morning our time. We'll give you a day to settle in and then we were wondering, if you feel able, would you mind if we went out for dinner on Monday night?
Of course not, I said. You two go and have a lovely night.
"That's what I'm going to be there for, I said confidently.
Inside, I'm terrified.
He's so little. And it's ages since I've been around babies. What if something goes wrong?
What if something happens on my watch?
I'm far more nervous about the prospect of minding my grandchild than I ever was at looking after my own baby.
Still, I feel privileged they want me there and to have a job that allows me the flexibility to go to London.
There are so many Kiwi grandparents whose offspring are flung far and wide throughout the world who barely see their grandchildren so I know how lucky I am.
My huge suitcase is loaded with presents for the baby - there is only room for a leather jacket and a change of knickers for me.
So many of my lovely ZB listeners have knitted exquisite little pieces for the baby; there are toys and books and tiny Red Band gumboots and a personalised Warriors strip from the team - this little boy is a very lucky man indeed.
The birth of a much-wanted baby is such a gift and brings so much pleasure to so many people. I cannot wait to meet him.
