My daughter plays this game but I worry about this alliance chat box. Are their any guidelines or restrictions..

Nope. No such restrictions.. its an open chat box.. no guidelines as well.

It's not a game for children. Don't let your kids play this game.

Several alliance are kid friendly. Another option is to message the alliance leader and ask them about chat policy. Request to not push her to talk in chat. Don't mention her gender or specific age- you don't know the leader either.

Well if chat box bothering you can choose to hide alliance chat option.