For a fun and girly portrait, dress your baby girl as a fairy, complete with a wand and wings. Hang a forest backdrop in a photo studio, with fake trees and glittery spray paint to give the background a sparkly glow. Or head outdoors to frame your little girl with real foliage. You can even commission an artist to paint over the portrait later to give it a more ethereal glow in keeping with the fairy theme.
In reference to Claude Monet's famous "Waterlilies" paintings, photograph your baby in a setting with trees, streams, lily pads, and perhaps even a wooden bridge. Dress her in pastels to create an Impressionist feel.
Famous photographer Richard Avedon photographed all types of people against a stark white background, seeing each of them in a unique, honest way. Use black-and-white with a lot of light and contrast to make even the subtlest details about your baby stand out.