Kate Middleton (and her burgeoning baby bump) could not possibly be any cuter!Catherine, Duchess of Cambridge paid a visit to The Fostering Network’s headquarters in London Friday, where she had met with foster caregivers, children and staff. The pregnant princess was all smiles for the occasion, looking every bit the yummy mummy in a chic brown dress with a belted bow tied around her waist.The experience seemed to be a positive one for Kate as well. Kensington Palace Instagrammed a photo of her smiling as she waved goodbye, writing, “Thanks to all the carers, children and staff at the Fostering Network who shared their stories with The Duchess of Cambridge this morning!”