Selective reduction for higher multiple pregnancies is offered in the UK although not widely broadcast as it's usually a private and difficult decision. I haven't read the Grazia article, or Grazia come to that, but I would imagine that the woman is feeling rightful and defiant as she feels the need to defend her actions. Who knows why she feels that way - maybe because she knows that people will judge her (and have judged her?).
I can't say what I'd feel like if I got pregnant with triplets. I have twins and I help run a twins club with a lot of members so I have come across triplet mothers - we have a few in the club (IVF and spontaneously conceived) and I'm under NO illusions about how hard parenting triplets is. There are no extra handouts or extra support for three babies - you're on your own. I suspect I'd feel sick to the pit of my stomach.
I wouldn't dream of questioning someone's decision to terminate a pregnancy. Their decision. My experience is that just because something can feel 100% right for you at that time doesn't mean that it's an emotionally easy or straightforward decision to make. Sometimes the right decision for you at that time can be acutely painful. People tend to forget that and just assume that abortion is chosen because someone wants to be able to fit into their tight jeans for their friend's 30th or other such trivialities. I mean, only shallow, cruel, heartless women actually have abortions don't they? They can't be considered, agonised, grieved over, accepted but painful?
I do question the Grazia lady's wisdom in writing about it so openly - on the one hand maybe it's good to get the subject out there and in the open, but on the other hand there's a large part of me that considers abortion/termination to be a private matter. There's a surviving 'triplet' to consider. Perhaps she's being brave about it, I don't know. Maybe it's the thought that she's being paid for the article (is she?) in which case it just turns into some sensationalist journo saga. Let me wave my banner and spew my emotional guts for $300 and pretend it's for the greater good.
As for hereditary/non hereditary, non identical twins are non hereditary and just the random splitting of an egg that no external or biological factors, inherent or otherwise, can influence. Non identical twins are hereditary as they occur from 'double ovulation' i.e. both ovaries producing an egg during a monthly cycle. If your mother, Grandmother (paternal or maternal), etc. were prone to double ovulation then there is a chance you will too and will conceive non identical twins. Triplets can be conceived naturally, either by a single embryo splitting three ways (producing identical triplets) or, more commonly, a double ovulation resulting in two embryos, one of which then splits into identical twins. NB: in a selective termination of triplets it is usually the identical twins of the pregnancy that are terminated, leaving the single embryo. You're more likely to conceive twins over the age of 35 - something to do with the body getting ready for menopause and 'dumping' eggs through double ovulation and if you live in East Africa - the latter is thought to influenced by an oestrogen-rich diet. Also if you're tall. It's also worth considering that twins are more likely to survive early pregnancy i.e. before 12 weeks due to women routinely taking folate supplements before and during pregnancy. The body, faced with having to build a central nervous system twice over, is more inclined to sustain a pregnancy that it has the building blocks to support.
Sorry for the long waffle. There's a lot of total crap spouted about twins/triplets which really annoys me. Top irritation is "Are they really harder than two singletons" but that's a whole other post.