Under their Children, press What are you trying to fix?, then Something else…, and choose the option saying one of their children is the wrong person. We'll ask who the child should really be: someone already on the tree, someone new, or keep a space. For example, if the tree shows the wrong man as your uncle's son, pick the right one, and the wrong one stays safe for wherever he belongs.
Where to find it
Person page (Safe edit on) → under Parents, Partners or Children → What are you trying to fix?
Only people with the "Add people" and "Remove" ticks, with Safe edit on.
Still stuck? Talk to a real person: send us a message, or email support@mywholefamilytree.com