4 month old being a mama's girl

My 4 month old is a huge mama's girl. She wants nothing to do with anyone else. She will scream and cry until I pick her up. I havent been away from her for more than an hour or two at a time since she has been born and when I have left her I guess she has fussed the entire time. My first was happy with everyone so I never had this problem. But, how do I get her to be happy with others? Do I just ignore the crying and let them soothe her? She will be happy with daddy as long as I am around. But, she even gets fussy with him. I'm kind of at a loss of what to do for her.

My 5 month old is the same way. I'm supposed to be going back to school soon and I'm worried she'll have a hard time.. Are you bfing?

Six month old is the same way. Just in the last month has she started to be okay with her dad and siblings. I have read the best thing to do is expose her to someone several times and make sure she has a chance to get to know them with you around.. But that hasn't worked for me