I was wondering if it could be something else. The fact that her 5-year-old brother, as well as my partner and I, are not catching the virus.

Based on the symptoms described, such as vomiting, fever, and frequent episodes of feeling unwell, it is possible that the individual is experiencing a gastrointestinal illness. It is important to prioritize basic hygiene measures, such as frequent handwashing and cleaning shared surfaces, to prevent the spread of the illness. If the symptoms persist despite these measures, it may be advisable to seek medical attention to rule out other possible causes.