Serendipity - yes, as I said up thread, about 25% of the women in the BMJ survey did enjoy anal. The overwhelming majority, 75%, did not.
This is an article aimed at 13 year olds. It's not "how to do something (which incidentally is illegal at your age) safely", it's about persuading them it's a normal, integral part of sex. Against a social context (quite different incidentally from my youth - I'm an old gimmer in her fifties) in which men are pressurising women into anal sex they don't want and don't enjoy.
The balance of the article is all wrong. Yes, teenagers are sexually curious. But 13 year old girls need above all reassurance. Reassurance that their bodies are their own and they get to say what does or does not happen to them. Reassurance that it's okay to be uncertain, it's okay to say no. Reassurance that their sexual pleasure matters (congratulations for being in the 25%, I'm glad you enjoy it - but the other 75% need to be empowered, in the proper, meaningful sense of empowered, to say "no, this isn't doing anything for me/is painful - and what the hell is sex about if not mutual pleasure?").
Deal with that stuff first, properly and thoroughly, and then maybe you can get onto "now here's a niche activity that about a quarter of women enjoy, and if you're in that quarter, here's how to do it safely."