It sounds more like she's dissing that he's rich. Basically, that other girls have to be nice to him because he has to power to ruin their reputation and their chance at getting a decent marriage -- something their livelihoods often depend on. If he wasn't rich, those girls would treat him as a rude and arrogant man (which isn't exactly untrue at that point in the story) and dismiss him.

That is also how his relative Lady Catherine behaves -- she has the power to ruin someone's livelihood if they displease her.

And also accusing him of having a "poor rich man" complex, and I guess she suspects him of pursuing her simply for sport. It was quite common for wealthy men to have mistresses before they got married.

So it is kind of a "not like other girls" but that's because a lot of other girls don't have the luxury of telling it like it is, so she's more saying, "I am just saying what other girls would say if their situations weren't dependent on finding a rich husband."