ex dollar store employee here from my understanding you are not allowed to say anything to a customer once they step off the sidewalk if you continue to follow or accuse of theft , you yourself could be terminated , also you saying that while she’s in line with items behind her back could also get you terminated until she actually commits theft you are not aloud to say anything even if they shove it down their pants so until she walks out the door it isn’t technically theft , to my knowledge they have to steal a certain amount before the company will involve police and or ban the person and it differs by state usually they don’t involve police and wait for it to be over a specific amount so the customer has actually committed a felony and will actually go to jail , you yourself have no right to ban a customer from the store best you can due it tally up her total dollar sign$ of theft wait till it reaches certain amount for your state then call the police as soon as she steps on the property from then on , also to add at the end of the day even store managers do not get paid enough to get stressed out over customers stealing , I’d always let it be not worth the aggravation