Congrats!
In 10 years, are kids on the playground going to find ever new and creative ways to butcher her first and last name to tease her? In 20 years, when she's applying for a job and gives her name is she going to be taken seriously or considered someone with a fad name or nickname?
Wife and I vote Anabelle. Lots of opportunities for cute, shortened versions and she can still put the long-form on a resume. (Our daughter is named Evelyn but we call her Evie, pronounced "E-V.")
Best of luck. It sinks in when you get a minute between the two of you, look at the kid, look at each other, and then say... "Now what?" =)