Brownish black stool could be due to certain things she has consumed like iron supplements, Oreo biscuits etc.
For the red spot if it is increasing in size or causing any discomfort or watering, u need to consult with an ophthalmologist.
Try giving her multivitamin for the cheek skin to heal. If that doesn't help kindly consult with your pediatrician
Next Steps
make sure she has plenty of fluids.