My 5 month old has a slight rash under her skin on the front of her left leg, its been there for 4 days now, she has been fine in her self but has woke up today with a cold. The rash hasnt got any worse but Im worried that it could be something wrong now that she has a cold
For rash on the leg you can give your daughter some antibiotics like syrup CEA Chat Doctor.  You can use college or renovate cream for local application. Don't worry she will be fine soon.