Quinceanera help

I'm not Hispanic but am Catholic and my eldest Hispanic niece is turning 15 😍😍😍 help this Auntie out! What do I need to know. About how much should I contribute to the party cost? The gift? This girl is super special to us but I also have multiple nieces and need to make it fair as well as Goddaughters and the Goddaughters will obviously be more. Help out this super excited auntie please!

*Specifically how much to contribute to her party? All family is contributing as per their family traditions. If I'm contributing to party do I also give a gift?

I've attended one previously but this is the first I'm involved more then a guest.