It seems to be mostly about playing games though -- I haven't found any equivalents of wall posts, or status updates, or comments, or messaging.
Here we go:
Ohanarama offers messaging among family members only. The Parent Account holder is responsible for approving individuals connected to the family and able to send/receive messages with children. An individual, adult or child, will not be able to message a child within Ohanarama without prior approval of the Parent Account holder.
That could work.
That seems to be just messaging, though.
Still not sure if it would be an interesting enough replacement for the means of communication she already has -- email, texting, etc.
Also it doesn't seem to be totally free. (You get a certain amount of "neuros" free but you seem to be goosed to buy more.... I dislike those kinds of sites.)
I'll keep an eye on it...