Word I think that when I went to Cambridge it was definitely harder for a female from a comp, working class, immigrant council flat background to get into cambridge to read Maths than it would be today. Maths at Cambridge was overwhelmingly dominated by male posh people. But obviously I didn't make it easy for myself, I could have picked a demographically more likely subject, for example.
Maths is an interesting one, mind you, because state school pupils are - gender notwithstanding - at a disadvantage in maths now, compared to posh school pupils, at not just Cambridge but lesser universities too. So. But for other subjects? The proportion of state school pupils is higher today.
As far as the city goes - I know your husband is partner level but you must know that you just cannot say 'I would have made it too' if you walk away beforehand. And many people make it to partner or director and still get shed, these days (not like when we were trainees and you could have truly terrible partners who everyone knew were terrible but who, by virtue of having been good for 5 minutes many years ago, were set for life. It just isn't like that any more - and it isn't for people exactly our age). In very broad terms, there is a wider pool of acceptable universities now than there used to be. It;s still a small pool. But it's bigger than it was in 1989. Firms still pay for training. Training is better, and more accessible too. Trainees are treated much better than they were in our day (and they have much better T&Cs).
I just don't believe that it would be impossible for someone from my background to do what I did, today - I don't believe it would be impossible for someone from my background but without my issues to do much better than I did. I don't see many, coming through - but I do see them. I think some things are easier now, some things are more difficult and the net effect is broadly neutral, if you leave aside debt.