I ask myself "Would I add this person if they were not related to a person I am a fan of?"
If the answer is "yes", I send an invite.
If the answer is "no", I do not.
Fortunately, with most of the sports I am a fan of, the competitors tend to be very nice, down-to-earth people. Unsurprisingly then, their families are as well. So, most times where I have sent an invite, there has not been any bother. In fact, I have had some very nice chats to the mothers of some motorbike racers I am a fan of. And some wives/girlfriends.
But, just because this has happened with the people I have added, doesn't mean that this is always what happens. I have just been fortunate.
Looking at the [URL="http://en.wikipedia.org/wiki/Big_Star%27s_Little_Star"]Wikipedia page[/URL] for the programme, and seeing the names of the celebrities, it is pretty obvious that the children involved are all VERY young. But, had they been teenagers or older, I would have been concerned that they could be getting unwanted attention online.
So, personally, I do not think that this is a wise concept for a TV show. Children should not be in the public eye, just because of who their parents are, if they do not want to be.
I should add, I have not sent Daria an invite. I felt that it would be highly inappropriate to do so at a time when she is being discussed on here in the manner she has been. Also, she only has 1 mutual friend with me, so that gave me the impression that she is not actively trying to be part of skating circles.
Which is fair enough. Just because her parents are famous in a certain field does not mean she has to move in the same circles.
She deserves to have whatever level of privacy she wants. Which is why I am respecting that.