Time flies, unless you're nine and waiting for someone, writes Jo Malone

Keola's caught me out again..

She misses her best confidant, big sister Sunny. She misses her so much that sometimes the ache is so intense she can't speak, but only nod when I ask if she's quiet or upset because she needs Sunny.

Time for Keola has dragged since Number One went to spend her second year of uni in Canada.

We visited at Christmas, but that magical two weeks when Keola, as she said, wasn't the oldest sister, went too fast and seems too long ago.

Now we can finally say that Sunny is home next month, which I thought would seem soon for Keola. But I'd forgotten how slowly time strolls when you're a child.

'My competition is in two weeks and you said that was ages,' Keola points out. I did, it felt helpful at the time.

Keola counts eight weeks until Sunny is back and it might as well be a lifetime. She's not actually sure she can imagine that long and I keep catching her watching the clock and rechecking her calendar.

It's heartbreaking to watch. I do my best, but there is no way my parenting comes anywhere close to being a big sister. I can't wait to see her either. I'm so proud she's thrived in these months so far away.

She left with just a teenage eye roll at my stream of 'have you got enough socks? Keep your bag zipped. Keep your drink with you. Are you sure you have enough socks? Remember your chargers and adaptors. I'll always come if you need me. Have you got a hat? Have you got a swimming costume, you might need one. Have you got pens? Take some warm socks. You will eat properly, won't you?' monologue which lasted all summer until she left.

Naturally I tucked a couple more pairs of socks into her suitcase as she left.

But now she's emailing me about dissertation topics such as 'Vividness of goals and temptations' and 'Is there a hemispheric specialisation in the pre-verbal infant?'

I'm delighted she's loving academia, but what if she comes back and isn't our Sunny, Number One, any more?

What if she won't let Thalia daub her with a serious amount of pink and purple glittery make up, or let them both draw all over her legs? Will she still pretend to drink Thalia's mixtures made from whatever Thalia can reach in the fridge and bathroom?

Will she still practice handstands in the hall and somersaults on the trampoline with Keola? Will she remember that Keola likes the idea of shopping but doesn't really want to try on clothes - although she will try on dozens of trainers and spend absolutely hours in a stationery shop?

Will she still put Keola to bed, with a lot of giggling and hanging upside down from Keola's cabin bed? Will she still play balancing angels, photo poses and try out the more acrobatic manoeuvres from Strictly?

Will she still be as patient with Thalia when she's being Thalia?

What if she's too grown-up to be the Sunny that Keola is waiting for?