DN is being raised vegan
We are not remotely 'hippy' or 'eccentric' but our children are vegetarian, its really not that uncommon.
She used elimination communication from being newborn
frankly I do not have the time, energy or patience but it hardly effects me if someone else does it. Same way I didn't terry towel etc...
Doesn’t allow sleepovers
My oldest is 17 and we have never hosted sleepovers and he has never been too one. Sleepovers really aren't that common, I went to one in my entire childhood.
or quite frankly anyone to babysit. Niece is 3 years old and as far as I’m aware her Mum has watched her twice over night and that was by staying at BIL and SIL house
so what? we don't let random people babysit only a lapse parent would. My family are gone and DH are getting old with health issues, his mam has watched our kids twice at our house. Believe it or not there is NOT a huge queue of people that line up to offer free childcare to your children when you have them.
Niece has never been in nursery and SIL has just announced plans to home educate.
Nursery is NOT a requirement, people often use it as childcare to return to work but its not greatly beneficial to a child.
Home school I do find weirder, Ive only known a few with teen kids and their kids severely behind because 'home schooling' just seemingly means 'removing them from school' not actually replacing it with anything. However for example a primary teacher would be perfectly capable of teaching her own kids the syllabus at home etc... (although I doubt they would want to work, come home and work again). Its only by later years there no way you can provide ALL the subject they need in depth as just one person.
Socialization is the bigger worry if removed from school but you said she is socialized.
OP I assume you do not hold children since you make a lot of very odd statements like thinking toddlers have sleepovers and that family just dying to offer free babysitting... they are wild ideas not in line with reality really.