You can always create a profile, put the one source on it, and then abandon it. Hopefully someone will come along later and add more to it. I feel if you have legitimate data saying that person existed, it's good to add that person for someone else to find, maybe even years later. And you're not adding to your 5K watchlist limit.
You do have to draw the line how far down that rabbit trail you go, because at some point you want to be entering data on your own line again. Sometimes I'll make a comment in the bio that this source includes x number of children, but not make profiles of the children. But at least the information you found isn't lost.