'Mummy Phase' have I done something wrong?

For the last couple of weeks my daughter (20 months old) has been going through a real 'Mummy phase' i think she's always been a "mummy's girl" since about 15-16 months in the sense of she'll always pick mummy to do things over daddy but lately it's been quite dramatic. She scream cries when i leave the room for nighttime, she won't let me finish my dinner (if she wants a cuddle or attention it HAS to be from Mummy, even when Daddy's free). Sometimes she'll even get jealous over other kids giving me attention and has started rejecting family members she used to adore if they offer to hold her hand or play (like i said, if Mummy's there they don't stand a chance). I'm just really worried, have i caused this in some way? Is it a negative thing to only want me THIS much? Weirdly she's absolutely fine for nursery drop off. I just feel so sorry for my husband and other family members as they of course adore her so much but they keep getting rejected by her.