Hi Elizabeth, welcome aboard. We can't really see what you have done because of the privacy settings, but I don't think you have done anything wrong. In WikiTree each person is supposed to have his/her own individual profile, so when you add a child to someone's profile it should result in the creation of a new profile. You don't really want to get rid of it.
There is something that bothers me though, but it would be a site issue, not your problem. Since you have already mentioned your daughter and granddaughter, I will go ahead and discuss it. Your daughter's profile does not show any children, but when I search the data base by your granddaughter's name, an "Unlisted Profile" entry shows up in the list with you as the manager. And when I look at your contributions list, I see that you have recently created two unlisted profiles for your daughter's children. This seems to me to pretty much blow your cover for unlisted profiles that probably represent living children, and I question whether the software should work this way. Your privacy settings seem not to be providing all the protection you might expect.
I hope a leader or tech person could comment on this and perhaps explain why we're set up this way. If nobody does within a day or two, I would be inclined to put up a new G2G post raising this issue. If you are willing to serve as the sample, the leaders would have a specific case to look at, but if not I would just describe the problem in general.
Finally, it looks like you're rolling on your part of the tree, so I'd hope you'll soon join us as a full member!