Sometimes it doesnt come in until labout starts, typical is the week or even longer before having pups. Labour can stimulate milk production though but its always a good idea to have milk replacer on hand when you are expecting puppys just incase the milk doesnt come in. It can happen so just be prepared, Im sure her vet can give her some advice as well tomorrow.
Id bet they start to come in the next couple days, are any of them filling up? I noticed the ones by the back end would fill first with my girls and then slowly almost each day the next set up would fill up. Is there any way she isnt as far along as she thinks? was there more then 1 tie? if so always a chance she took on one of the last ties?