My daughter is on day 7 of being sick. she had 2 negative rapid strep tests. drs called today and culture came back +. she had a fever the first couple days and still has congestion and coughing. she is 23 months. does she have to take an antibiotic?

Your baby has been sick and her cultures were positive for step. That sounds like a good reason for her to take the antibiotics your doctor prescribes, before further complications develop.

Yes. She needs to be treated with an antibiotic to treat the strep infection and prevent complications, like rheumatic fever, that can result from such infection.