Now typically if she were gravid she would be clued to the heat and not roaming the tub, she also wouldn't be doing any bowl wrapping.

Based on the info in this thread I'd say she is likely not gravid but I would take her out and attempt to palpate her again. Once you get your hand in correct position don't be afraid to really use some pressure.

Once you get to that bottom third of the body you'll know very soon. If it takes a couple tries then do it, it won't harm her it'll just make her a little uncomfortable

Hope this helps. Good luck
larry