My daughter of 5 keeps going to the toilet is this an infection and if so what can she take ?

Can't diagnose: with the available information. I suggest that she see her pediatrician who can do a urinalysis.

Take her to doctor: If your daughter has increased frequency of urination, but produces less urine when she goes, or has constant urge to pee then she likely has a urinary tract infection and needs appropriate antibiotics. See a doctor right away before infection ascends to kidneys which can be an extremely serious complication leading to sepsis. Other symptoms may include fever, burning with urination, belly pain

Ist step: Is to obtain a urinalysis and culture. Other symptoms that you should check for is increased thirst and weight loss which would be a concern for diabetes. Symptoms of a UTI would be burning and perhaps fever and back pain as well as frequency and urgency. It also may have become a habit. Have her checked.

Irritation: The majority of these at her age turn out to be triggered by irritation around the pee hole. This often occurs when they sit & dwell in a soapy tub. Each time they cross their legs they gape & allow soap suds to enter. If the material is not rinsed well with clean water it forms a soap film that irritates. This can trigger itching/digging and frequent voiding. It can also cause a UTI. Needs visit