1. Drug interactions: Snow chrysanthemum and rose both have medicinal value, but they contain different components. If they are brewed together, they may interact with each other, affecting the efficacy or producing adverse reactions.

2. Allergic reactions: Some people may be allergic to chamomile or rosehips, and brewing them together will increase the risk of allergy.

3. Digestive problems: If too much chamomile and rosebuds are brewed together, it may cause digestive problems such as abdominal bloating and diarrhea.

4. Cross-contamination: Having the same cups or containers to steep in may cause cross-contamination if not handled correctly.

So, before using chamomile and rose water, it is best to consult a doctor or professional advice, or according to personal circumstances in the right amount with the use of.