If your baby is still crying not because of any of the reasons stated by Serene, it could be the constant change in environment that's alarming your daughter.. Try to sooth her by singing her a lullaby.. She'll relax once she hears your voice..
Another reason could be she's colicky.. There are some over the counter anti-colic meds which you can add to your daughter's feed..
Don't worry, I'm sure you're not the only one experiencing this.. My boy occasionally cries for an hour for no reason at all too.. Not hungry, not wet, just asking for attention..
Just be patient and make her comfortable..
change of environment i agreed
as i believe you all are weekend parents if i'm not mistaken
so somehow your kid is attach to the babysitter
what you can do is
next time let the babysitter tag along and see what is the reaction
if she did not cry
thats mean she's attach to the babysitter
so slowly you need to let your child knows who you are
when shes asleep, you might wanna kiss her forehead once in a while
let her feel your spiritual bonding thru her sleep
colicky? i dont thing so as babies will clear of their colicky within 6 mths