I think that last post has crystallised, for me, not just the racism but also the cake-ism in this woman's attitude.
As a Muslim woman who chooses to wear a hijab, she's probably better off in the UK than just about anywhere else in the world. She has equal rights to men and legal protection against sex based discrimination, which she probably wouldn't have in just about any Islamic country you can think of. At the same time she has legal protection against discrimination on grounds of her religious beliefs. The Equality Act gives her all these rights, clearly enshrined in law. She is living in a country where Islam is not a majority religion and most people do not share her beliefs, but if she wants to wear a hijab at school or at work, or a burkini on the beach, she is allowed to do so (unlike in certain other Western countries). British people are, on the whole, pretty tolerant and accepting, but if anyone commits a crime against her motivated by either her race or religion, this is considered a hate crime, attracting a harsher punishment under the law. The UK is even - in stark contrast to the rest of the western world - clamping down on men in women's single sex spaces. Not for her benefit, but it will certainly benefit her.
It is difficult to think of any country where she would be better off living than the UK, and yet, should she decide she is better off elsewhere, there are many other countries where Islam is the official religion.
Jewish people, on the other hand, have precisely one country in the world where Judaism is the official religion, which was controversially granted to them after they had spent centuries being hounded out of just about every other country, and recently been the victims of a major genocide. And now, according to many people, they are wrong for supporting the existence of that country, or wanting to live there, or even continuing to practise their own religion in an unobtrusive way even if they don't support the existence of Israel or want to live there.
To the point where this woman, enjoying her full rights to live in and practise her religion in the UK and wear her hijab in a professional environment, has a visceral reaction to a Jewish woman not just wearing a Star of David, but essentially being allowed to exist in the UK.
Because she didn't say the OP shouldn't be wearing a Star of David, which would have been hypocritical enough. She suggested that if she'd known the OP was Jewish she wouldn't have consented to being taught by her. Which really suggests that she thinks the OP shouldn't be in the UK. But also shouldn't be in Israel, presumably.
So where does she think Jewish people should be allowed to live?