‘Since when were you the Instagram queen?’ Becky tucks back a strand of hair that’s escaped from behind her ear. She’s had it cut into a sleek graduated bob, which makes her look like a proper grown-up, especially as she’s still dressed in her work clothes of grey slim-fitting trousers and a pale blouse made of silky stuff, which I would definitely have spilled coffee on within an hour. But she’s here at 6.30 p.m. looking as if she’s just got out of the shower, instead of having battled her way home through London traffic after a long day doing corporate law stuff. I’ve taken off my pink fluffy coat because it was making me feel like a dislodged tree bauble, or a pom-pom, in comparison to Becky’s minimalist chic.

‘Hardly,’ I say, fiddling with a filter and making the photo look nice before hashtagging it and hitting share. ‘I just thought it’d be nice to show everyone back home what it’s like living in London.’

‘And make a point of what a lovely time you’re having even though they all think you’re insane to give up a promotion in Bournemouth for a pay cut up here?’ she says.

I nod, and pick up a tortilla chip, breaking it in half. ‘That too,’ I admit, making a face. ‘And Nanna Beth is on there too – she’s got herself an iPhone contract. I’m her only Instagram follower so far.’

‘She’s going to be sharing selfies with all the hot doctors in the nursing home, isn’t she?’ Becky snorts with laughter.

I turn the phone so she can see it. @nanna_beth1939 has posted a string of photos of her new ground-floor flat in the sheltered accommodation unit she’s moved into.

‘Oh, bless,’ says Becky, taking my phone so she can have a closer look. ‘Look, she’s got that wooden carving you bought her in Cyprus on the mantelpiece.’

I peer over her shoulder. ‘Ahh, that’s nice.’ I’m hit by a wave of guilt that I’m going to be up here and she’s going to be down there. I’ve spent the last year living in her house, ever since Grandpa died, and it’s going to be weird not having her there every night when I get home from work.

‘She’ll be fine,’ says Becky, as if reading my thoughts. She clicks the phone off and puts it down on the table. ‘And it’s not as if you’re miles away. It’s a train ride, that’s all.’

‘I know. Just feels weird leaving her to the tender mercies of Mum.’

Becky makes a face. ‘Yeah, well, she’s not exactly . . . well, she wasn’t at the front of the queue when they were giving out the nurturing quota, was she?’