Mine have both been like that when they were young babies. It helped to leave the baby at home while I went to the shops on the weekends. They can behave very differently when mum's not around. If my baby can see me, he'll always cry for me to hold him, but if I'm not in the room, he's a lot better. I think they need time with their dad so that they learn that they can trust someone other than mum. It must be so hard for the poor dads who miss the baby all day, and come home to a response like that. She will improve eventually.