Genuinely, I loathe the 11+.
There are 2 counties remaining in the UK that have the Grammar/Secondary Modern system, Bucks and Kent, but I believe stand alone and private Grammar schools exist elsewhere. I live in one of those counties and I have taught in both types of school, currently Secondary Modern.
Kids get tutored to within an inch of their life to get to GS. It’s crazy. It causes an economic divide - those who can afford tutors and those who cannot. So the richer kid’s disproportionately go to GS. And honestly, once they get there, some struggle because they can’t keep up academically. It doesn’t always work out.
I didn’t tutor mine. My son went to grammar. My daughter didn’t. At his school the sport is amazing - rugby trips, cricket trips to far off places, they even have fencing and rowing. Music is outstanding and he has benefitted from enhanced facilities courtesy of PTA and generous old pupil donations. We couldn’t complain.
However, at my daughters school the roof leaks. We don’t have much sport and music. Or trips. But we do have some fantastic kids, and we also have some that need a lot of love because everybody goes to school. We have disproportionate SEND and ESL and that can be hard, but only the same funding, but guess what? The teaching is Exactly The Same. We teach the same curriculum and the staff care just as much (I know because I teach there.)
I’d say if you can afford a decent private education at a good school, good for you. If not I prefer a good old properly funded Comprehensive above the grammar school/sec modern any day because why should my children have been separated into a first and second class education at such a young age? The 11+ is one exam taken at 10 years old (actually my son was only 9) and it causes so much distress. Great if they pass, but if you accept that you also have to accept the concept of more able children being provided better facilities, and less able pupils having to cope with less which then further reduces their chances in life.
As to your friend, she’s only insecure. Grammar schools are not begging to get her son (except some private schools desperately trying to fill their rolls). My sons school is are fending parents off! Personally, next time she phones I’d be tempted to say, ‘Good for you, but this is what we’re doing.’ Then leave it at that.