What's up with you? ---> Qué pasa contigo?
Baby your fine! ---> Nena, estás bien!!!!!!!!!
Just too cute ---> Simplemente demasiado lindo
Spoiled and you know it ----> Consentida(o) y lo sabes
Mama's little man ---> El niñito de Mama
Precious (which by the way is my baby daughter's name) ---> Preciosa
Christopher (my baby son) ---> Cristobal
This is a non'commercial forum, so I won´t give you the links, but if you go to Google or another search engine, and type the name of a famous greeting card company, and the word ´tarjetas´, you will find a huge collection of sayings like the ones you wanted to translate!