Ffs so according to mumsnet if you have got money behind you then don’t get married.
Not mumsnet. Some posters have this opinion. I am one of them, however, we are not 'mumsnet'
And its not about 'money or relationship', many people can have extremely fulfilling relationships without joining finances with people.
Tbh, suggesting that you can't have a fullfilling relationship, without joining finances, sounds quite mercenary in itself.
People who say money doesn't bring happiness are woefully naive. No one believes it brings happiness. But it does bring a certain amount of security and a hell of a lot of choices. That's what it brings. Relationships often fail due to money. More often than not, due to a lack of it.
Op asked about telling her dp. It's some people's opinions, that she doesn't need to. Just an opinion.
But so many are so outraged that anyone would dare venture that opinion.
If you got married and share finances, great. You and your spouse are on the same page and everything great. So crack on.
Neither opinion is more valid. They are peoples opinions. Different points if view based on different lives and experiences.
And I don't think anyone told op to hide it. Unless you think she is hiding it now. It appears that she just never brought it up. If you think op not disclosing this is 'hiding her money', surely you think she is already deceiving her partner, so probably should not be getting married to a partner she is actively deceiving already.