hi... my parents for my 30th gave me for upcoming cruise.. sunscreen, book, cards (for plane ride) film... and the big part.. shipboard credit.. they took pieces of paper and got disney stickers and decorated the paper and then wrote on the dollar amt... (then they told me to bring those to Pursar's office.. cute arent they?)
also.. if her actual bday is while on board.. one year for my aunt.. we decorated her door so that everyone who walked by her room knew it was her bday! my parents brought the tape w/them and asked cabin steward for scissors when needed.. they did it after she went to bed the night before.. and she loved it!
hope that gives you some ideas!