Your tips for the server/assistant server/head server and stateroom host will total $162 for the 3 of you for 4 nts. Those are automatically added to your account. (They can be lowered or raised at guest services, but the 'suggested' $13.50/day for each of you is a pretty standard cruise tip amount.)
Everything else is up to you...all 'regular' food is included (upcharge for Palo/Remy adult restaurants, the ice cream/sweet shop, movie candy/popcorn, and some food in the bars.) Non alcoholic drinks on the pool deck/buffet/ and the main dining rooms are free. Anything from a bar will cost $. Basic coffee in the MDR/buffet/and self service beverage area is free...if you get it from Cove Cafe or Vista Cafe, that'll cost $ (note that while the drinks cost $ in those places, the snacks there are free!)
I generally budget $25/day for 'extra' beverages--1-2 alcoholic ones for me, 1-2 specialty non-alcoholic ones for DH and the kids--like smoothies, etc.
When you book stuff during your online checkin, you'll see the prices for any drink tastings/spa treatments/port adventures, etc.
And only you know what your family is like for souvenir shopping...is everyone going to buy a $40 shirt or a Tervis mug...or just a magnet/ornament...or all of the above. I have 1 kid that is a 'shopper' and 1 that is very picky and will get 1 thing. For myself, I might spend $50 total. You can set a budget for everyone...I think that $50/person in the shops is reasonable.