I disagree. Technically she is now a member of Royal family who sister will be Queen consort of the British Commonwealth. She is now a member of society unlike reality TV stars.
I would put it another way, Pippa is not a”member”of the royal family but by extension to her sister who will one day (if all goes well) will one day be the Queen consort and as such she and the rest of her family will have to be mindful of things they do.