Your daughter is fine. She just had a little something 'extra' during that bath time.
I feel I must defend you from the moms that are scolding you and giving you guilt trips about keeping an eye on your child. We all know being a mom is a tough job. Having more than one child makes it tougher. I'm sure you were watching her during her bath- otherwise, you wouldn't have noticed the water inadvertently entering her mouth and wouldn't be asking your question here in this forum.
As a working microbiologist, there is bacteria everywhere- good bacteria and bad bacteria. There was already lots of bacteria sitting in the tub before it was filled with water, on your shampoo bottles, soap, toothbrushes, you name it. There is also bacteria in the tap water we all use on a daily basis. So, we cannot wrap our kids in bubbles to make sure we keep an eye on them because everyone with an immune system is exposed to bacteria. If you eat yogurt, you are eating bacteria.
Fecal material has all the nutrients that opportunistic pathogens need to grow and flourish. If fecal material sits around long enough, then it will be harmful when eaten.