3 year old with fever and diarrhea

Ella

So basically my daughter slept over my mothers house from the 29th to the 31st and then came home, like two days later she woke with a fever and diarrhea. She must have used the bathroom like a bunch of times, this lasted like 2 days and then day 3 the diarrhea calmed down and she only went like 3 times compared to the other days. Only at night has her fever went high, heights being 103, Motrin drops her fever immediately thank god. Anyways her fevers have been low grade throughout the day and even dropping to 99 and she’s active all day, eats and drinks, plenty of fluids as well, no dehydration. Today is day four, around 7am her temp read 102.2 she woke feeling awful, I gave her some Motrin and three hours later when she actually woke up at the time she usually does, she’s better again. No vomiting at all. Only when her temperature seems to hit a certain number does she feel awful but once it drops she’s back to usual.

No other symptoms.

Now the day after she got sick, my 1 year old had a fever for a few hours and then it broke and it never came back and the family isn’t sick, I assumed she has a stomach bug because when she was with my mother their was only two times she could have gotten sick, once when she went to the store with my mother and two when my mother said she caught her drinking some sort of rain water from a bucket in my mothers yard though I don’t know how long it was there, obviously she stopped her at that point.

Other than that she’s been fine, she eats and she drinks water and pedialyte pops to make up for the loss.

Day four her fever is low or barely there, just feeling her forehead and it’s barely hot like it was three hours ago, she gets tired of me checking her so when I know she isn’t hot I know she’s fine and she’s had diarrhea once so far today but not like dramatic and she didn’t complain of stomach pain. I just want to know if this has happened to anyone and when should be the time limit to take her in like by how many days?