If you have a look at the Aspen Proposal, you will see that it does indeed suggest a smaller population than the current 8 billion or the peak 10 billion. Fortunately, birth rates are falling everywhere and we should be able to ease our numbers down over a few centuries.

The "family" is all the species that co-evolved with us from common ancestors. Which is all the species on earth. One of the reasons humans are mucking things up, is that we only see our selves as human and not as part of a large extended family. Changing that mindset may help us fit in on this planet a little better.