THE new school term has begun and a handful of mothers -- some friends of mine -- have added to their families. They now have three children, four in one case.

As little as a year ago, I would have been green with envy. Despite being a mother-of-two in my early forties, I hankered after another baby. I couldn't shake off the feeling that my family was incomplete and that I needed another daughter (I'd always dreamed of having three girls) to finish things off.

Ideally I would have had them all close together, as the first two were. But exhaustion and nursery fees meant we waited...and waited...and finally when I was ready -- sometimes last year -- we tried (albeit halfheartedly in our normal exhausted state) a few times without success.

Then, about six months ago, the maternal part of my brain (which my husband would probably claim was around two per cent) performed what they refer to in political circles as a U-turn.

It started with a trip to London. Oh, the nightmarish problems we had in attempting to sit together on the train, the immense difficulties in negotiating the Underground with two small children during rush hour, and the vast expense of eating out -- something which, other than on occasional picnics and outings to fish and chip restaurants at the seaside -- we rarely do.

That experience, plus the problems of day-to-day child-rearing, made me think twice about adding to our family. After much thought, I concluded that any more than two is not a good idea because:

You only have two hands for crossing roads, visiting crowded shopping centres and the like. A third child would be a loose cannon.

Our small family car only has room for a couple of child seats and I would rather drive around in a tractor than splash out on a giant gas-guzzling so-called 'people carrier'.

Three sets of 'fickle-beyond-belief' taste buds at the dinner table would be more than I could handle.

The cost of extra airline seats would mean going abroad -- something we plan to do with our daughters in the medium-term future -- would be out of the question.

Isn't it the case that most 'family tickets' to tourist attractions admit up to four?

What would happen at the fun fair or theme park, where most rides are two seater? I would probably -- at the age of 50+ -- end up having to sit in some G-Force monstrosity just to make up the numbers.

Catering for two lots of after-school/weekend activites is difficult enough.Three would be virtually impossible.

The potential for arguments would be increased by at least a third.

Being one of three children myself, I realise that there are some advantages to having a larger family.

I love the idea of constant activity in the house -- as there always was in ours when I was growing up -- and I hate the fact that the children are growing up fast, and won't be children for long.

I expect there will be some regrets, but I think for us there's a lot of mileage in the expression "two's company..."