She will pour me a glass of wine and we'll watch the latest episode of Lost in bed a and discuss, as we like to do, what kind of people we would be if marooned on a desert island.
Obviously, we would be indispensable and have killer tans to boot. I would be a pot-stirring, plant-stroking type who runs around plucking dock leaves for anyone stung by a nettle.
My sister would build huts, make weapons out of palm fronds, and kill everything in sight. We both know the fantasy versions of ourselves to be just that.
The truth is, we're so petrified of nature that when our parents took us to Disney World as children, we screamed all the way round Discovery Island, which is man-made, and finally had to be restrained, escorted back to the mainland and, erm, left there. For us, nature means spiders, and spiders mean hysteria.
Anyway, I digress. Today there is trouble on the British mainland. My sister is moving out of her flat.
"When?" I demand, shocked. Usually, if my sister sneezes I know about it.
"In three days. Come and hold this chair while I fit the smoke alarm." My evening of pampering has been harpooned.
This has been coming for a while. My sister has lived alone for years – like all successful young women in London, it seems – but she fancies a change. She wants company, for someone else to turn off the lights now and then, to make her a cup of tea, listen to her woes. "Yes," I nod, staring longingly at the unboiled kettle. "I know exactly how you feel."
What she doesn't realise is that living alone has turned her into a little warrior – a female Oddjob – who laughs in the face of DIY dramas and runs mice over with her washing machine. (She really did do this. I know because I was on the phone, giving moral support.)
During the course of the evening, she hires a man with a van, packs five boxes, organises storage space and straightens her hair. When I arrive, she's standing on a chair outside her flat (she really is very small) and screaming while slapping her shoe against a spider the size of a pinhead in the doorway. See? She has the courage of a lion.
But I fear the move will transform her into something more like the mouse squashed by the washing machine within a week. That's because my sister is moving back in with Ma Ramaswamy until she finds somewhere suitable to rent. Of course she is.
Where else do grown-ups go in the 21st century but back to the womb? And I know exactly how this is going to end. Going home to Ma R will do nothing for her desert island survival skills. I feel jealous already.
This article was first published in The Scotland on Sunday, April 18, 2010