Does she looks constipated or not with her dirty diapers can he she is still learning to use her mussels so she will strain(alot of newborns go through that) there is also a growth spurr around that age xan be the reason she is fussy thats why she prefers the bf tobgive bottke when they fussy they do and want weird stuff but i would recommend is this continue to go nd see a doctor as mixed feeding can maby give het cramps thats whycis she is also fussy and try to do the "i kove you" massage it works isnthete are Cramps tgen you will know as the passing gas can be a indicator of either constipation or cramps