Is your DD at private school, OP? Are the friends who give more pocket money other parents of private school children?
I don't have anything like your household income (divorced so single-income household), but I have friends who probably earn similar to you and I don't think any of them are giving that level of pocket money. DC all in state schools, too. I can't imagine what a child of that age could spend it on.
Even if she's buying clothes, I can't get my head around that. I don't have £80 a month to spend on clothes myself!
Mine got a token amount in late primary school.
DC1 (17) gets £30 per month pocket money from me. XH doesn't give anything and XH and I split the cost of mobile phone, gym membership and another sport.
DC2 (14) gets £20 per month. Also nothing from XH, and XH and I share the cost of mobile phone and a weekly club.
XH doesn't believe in pocket money, apparently. Unclear how he expects them to have any kind of social life.
I give them a little extra in school holidays, when they are more likely to meet friends for a coffee or chips or something. And I offer to use my various loyalty rewards to cover cinema tickets.
They also often get money for Christmas and birthdays now, as they don't tend to want much stuff. Both are managing to save.