Yes, it is an opinions board, but Loxandra stated that the name
Lysandra is made up. She didn't state that it sounded made up, which would have been an opinion, but that it IS made up, which if correct would have been a fact. Morsa pointed out that it is not made up, which is a fact. Loxandra then responded, "That is what I think." Which would have been fine if she were defending an opinion, such as, "It sounds made-up" "It's ugly" or "It makes me want to throw up." But she was responding to someone correcting something she had stated as a FACT.
It's an opinions board, but sometimes facts do come into the discussion, and when someone erroneously reports something as a fact, there's nothing wrong with pointing that out to them, and if they refuse to recognize that they're incorrect, there's nothing wrong with pointing that out either.