i havent smoked since i was pg with ds1 (made ms worse)
but could it be possible shes not eating "right"?
only as with ds1 and dd, i could feed them fine untill arround 2 months when id slip back into my bad eating habbits (snacking on crap instead of meals) they started to get like you descriobed, constantly upset and unsettled
but the minute i put them on formula at 4 months, they were fine.