My daughter has a friend who had gotten mono, my daughter has no symptoms but what should i watch for to see if she does have mono?

Symptoms vary: The most common symptom, especially in teenagers, is a sore throat. However, this is by no means a universal finding. She could get swollen lymph nodes, belly pain (especially in the upper abdomen), extreme fatigue or something as simple as just feeling a bit under the weather. Incubations can be 7-21 days, so keep vigilant over the next few weeks.