Should I throw my sister baby shower at a all you can eat restaurant.?

My sister is the cook in the family and no one else can really cook so I was thinking of having her baby shower in a banquet room at one of the all you can eat restaurants and just bringing a cake and the games and decorations since a caterer is very expensive but should i make the guest pay for themselves or should i pay for them it is mostly family and close friends of hers.