Group G Strep, anyone heard of it?

I have tried to google but can’t find any symptoms for it. I was asked to babysit my nephew who is one years old for 2 weeks and was told he had strep but was on his 6th day of antibiotics so I figured he was not contagious. Shortly after being dropped off I realized he was still very sick. He had diarrhea, vomiting, cough, horrible runny nose, and very fussy. I have a 3 month old so I asked his mom to find someone else to get him the next day and keep him because it wasn’t worth my daughter getting sick. When he was picked up o was told by his step dad that he had a rare strain of strep called group G strep, and I’ve never heard of that before. Does anyone know what the symptoms are or have experience with this strain? My 6 year old is now vomiting, very fatigued, and complaining of a sore throat, I’m now even more scared for not only him but my daughter too. I plan to take him to the doctor but I’m not sure if they will be open because of Hurricane Michael that just hit us