returning player help?

[Niwashi]

It sounds like you bought the game for your PSN account rather than for hers. That's why it's asking for a code when trying to start it from her account, where it doesn't have a purchase recorded. The game doesn't require PSN+, but it does require a purchase for whichever PSN account is going to be using it. (It can either be bought through PSN itself, or bought from a third party. In the later case you'd get a code to enter into PSN to register that copy to that PSN account.)

I'm not sure whether the copy bought from your PSN account can somehow be moved to hers or not. Is her PSN a sub-account of yours?

And yes, the game is cross-platform. To both be able to play together you'll want two different SE accounts, your PC copy registered to the account that you play and your daughter's PS3 copy registered to a separate account that she could play.

If you can't get the copy you bought on PSN moved over to her PSN account (and I don't know how you'd go about doing that), then could you let her play from your PSN account? It sounds like your PSN account is already tied to a Square Enix service account (probably set up back during beta), but if it's not the one you're using, would you have a problem with her using it?