I agree with the previous responses---especially with breastfed babies their poops will tend to be a lot looser at times, especially teething too. As their systems mature too, there will be changes. If she is not uncomfortable and she is still eating well, it's probably just her system, but i would also just keep track of what you are eating to see if there is a correlation, like anything spicy or citrus and milk. Maybe just reduce these foods and see if anything changes. But also note that even if you change your diet it could take weeks to show any difference like you said! Could it be anything from the teething tablets? you could ask your doctor about trying more of those natural teething drops which I think have mainly chamomille in it, which may help settle her tummy too.