If your 3-year-old daughter is experiencing small, yellowish, and foul-smelling vaginal discharge, it is important to monitor the situation. The body is usually capable of combating minor bacteria that may enter the vaginal area. If the redness disappears within 5 days and there are no other symptoms, there is usually no cause for concern. However, if the redness persists, the discharge continues, or if your daughter develops a fever or stomach pains, it is advisable to consult a doctor.