My sister, S, moved to America last year and, when I have time to think, I miss her terribly. One of the positives, however, is the time difference: when it is 1am here, it is only 8pm over there.

Lately, 1am has been the hour when I start to lose my mind. I aim to be in bed before midnight, but, instead, I wander around aimlessly when the children have gone to sleep: I eat white bread-and-butter sandwiches even though I'm not hungry; I half-watch rubbish on the telly and I tidy up by putting everything into haphazard piles. What I should really be doing is catching up on sleep.

With only a couple of days to go until the abortion, I feel lost. R is often away from the house, partly because he says he feels miserable and doesn't want to inflict himself on us, but also because he is drinking again and now he always does that alone. His absence is often based on such arbitrary reason, and it does not take away from the fact that he could be here with us, performing his role as father and husband.

I dial S's number while in bed.

"It's me. Is this a bad time?" I say. One of the things we both understand is that when you become a parent, there is seldom a good time for a proper conversation.

"No! I've just buggered up dinner so I've ordered a takeaway. I have ages. How are you?"

We talk about our children, husbands, mutual friends, and minor hangovers made worse from sleep deprivation. In just a few weeks we will be together at our parents' house, and we chat excitedly about the things we will do.

"I have something to tell you, but I want you to know that I've made a decision and I'm fine about it before I begin," I say.

"You're pregnant." She knows me well.

"Yes."

"Oh, darling. You said you were feeling sick and tired. I kind of wondered," she says.

"I think I'm fine, and I've made the decision that I'm not going to keep it."

"Oh, my love. Are you sure you're fine?" S says.

"Yes, I think it's just R and me that aren't. He's drinking again, and this is just the result of us being irresponsible. I feel so embarrassed."

"Oh forget that. We all make mistakes. I'm just sad for you. But it sounds like you know what you want to do. And I'm here for you completely."

"Thank you," I say, feeling the cool stinging trickle of tears on my cheek as they fall to the pillow. "I don't want to ruin your happiness at the moment. Babies are such lovely things," I say.

S has just given birth to a girl, her second child, and I can't wait to meet her.

"Oh, you're not. And she's gorgeous, but she's a beast. She's sucking the life out of me."

"Babies are lovely, but hard work. And when they grow up … Well, I kind of thought they'd get easier, but they haven't!" I say, laughing through tears.

S and I have always shared the best and worst of times, and we have managed to help each other through with good humour, despite there often being no resolution to some situations. There is nobody like my sister and although I know that distance is such a minor thing when real love and friendship are concerned, I sometimes want to sit with her, feel her warmth, see her face.

"I wish I was with you … I mean now, but also on the day. Is R going?" S asks.

"I want him to be there, but sometimes I think I'd rather have someone else. Of course, I haven't told anyone, so it'll have to be him."

As if on cue, the call is interrupted by the jangle and clink of R's keys, as he attempts clumsily to unlock the door. I know he will head straight for the sofa, but I hastily turn off my bedside light to avoid the possibility of a sad-eyed, drunken chat.

My sister and I say our goodbyes (me in a whisper), and I turn the pillow over to the dry, cool side. It is nearly 2am, but I feel so much better than I did an hour ago.

I really wish S could be here now. It'll be hard to tell whether R will be up to the job of hand-holding when I go into the clinic to have the abortion.