This isn't really just the royal family, its the wedding party. Those, and the ones on the otherside, are her flower girl and pageboys, probably extending family or friends
Considering how much the UK gets back from the land that's been leased to them by the royal family, you can hardly consider them parasites. It's pretty valuable property that more than pays for whatever allowance is given to them.
https://www.youtube.com/watch?v=bhyYgnhhKFw
https://www.youtube.com/watch?v=bhyYgnhhKFw
I finished marathoning Altered Carbon a few weeks ago.