Yesterday was my sister's birthday, tomorrow will be mine. I am the elder by four years. We rarely see one another now. We live a mere six hours' drive distance from one another, but the occasions when we travel from my city to hers have become remote; the last time she travelled from her city to mine was thirty years ago, never repeated.

We do not even speak on the telephone with one another with anything remotely resembling regularity. Usually I call her, and on the rare occasion she will initiate that call. Even so, those times are incredibly infrequent. The four years' distance between us when we were growing up as young girls in our parents' home guaranteed few similar interests. And I was out of my parents' home by the time I was eighteen, married.

I was so relieved to leave the family home. Having experienced the misery of living with a mother whose volatile temper could and would erupt with amazing regularity and often without any discernible warning. Besides which, I could see nothing I wanted more in my future than to live with the boy who became my husband. Whom my parents had found wanting, his fault being who his own parents were.

My sister and I have far more in common with one another now; despite the age differential, for growing older, considerably older, diminishes the slight distance in age. When we do speak with one another, the conversation tends to be long and sometimes involved, replete with reminiscences as we grow older.

Once we exhaust the topic of family, and how our children are getting on with their lives, and the news of our grandchildren, we tend to move on to world affairs and also to animal welfare, a topic she is intimately involved with. The topic of our mutual health concerns ranks fairly high, since she has always had some health issues - and now I've joined her in that category.

This last conversation had its highlights and its low points. The distance between us is diminishing as far as our interests and conclusions are concerned, just as the physical, geographical distance appears to be expanding.