Patient, came to pharmacy today at 9:00am for a scheduled Covid vaccine. This was her first Covid shot and she was accompanied by her mother and two sisters. She was the last sister to receive her vaccine (3rd in line). After checking everyone felt well after their vaccination, I asked the family to wait around for 15 minutes and provided her with a timer set to 15 minutes. The family proceeded to shop in the store. About 5 to 10 minutes later, I was asked by a COS in the store to come and check on a member that had appeared to have fainted in the store. Upon arrival, PT  was conscience but reported feeling light-headed and nauseous. We got her a wheelchair and rolled her to the pharmacy immunization room. There, I asked PT and her mother several questions; such as, I know you filled out the consent form and everything was no, but has this ever happened before; did she receive HPV vaccine and have this happen (fainting is a common side effect of HPV vaccine/ mother reports that she had not received that vaccine and has never had trouble with any vaccines in the past.) I checked PT blood pressure for the first time at 9:45am and it was 94/74 and her pulse with regular in rhythm beating at a steady rate. I also checked her temperature at this time and it was normal at 97.4. I looked at the injection site and there was nothing significant to report. I repeatedly asked her how she was feeling and provided her was crackers and water even that she stated she had eaten cereal and drank water shortly before arriving at the pharmacy. She reported the crackers/water helped with the nausea but she still felt light- headed. Now about 5 to 10 minutes had passed, so I checked her bp again and it was 100/80. Her mother said that when she came to from fainting, she said she could not remember anything that had happened. I offered her a cool compress for her forehead and asked her to lay down on mat; however, she said she felt better sitting. Her father and younger bother did come as well. The father reports both himself and wife did fine with vaccine and his parents did well too. I told everyone present that her pulse was steady and the blood pressure was not dropping. I asked if they felt she needed farther assistance and I was wanted to monitor her for a full 30 minutes. I did check her bp for third time. It was still 100/80 and her pulse maintained regular. At this time the dad was ready to take her home. I asked her to rest today and drink plenty of water. I did also try to call the mother's cellphone with no answer around 1:45pm to check on her. I called again at 4:20 and  her mother reports she is feeling much better. I did take the time to recommend PT let all provider know she has fainted for a vaccine going forward and that she stay seated longer than the average person after receiving a vaccine and maybe even drink water after. I also informed that mother for the next vaccine I would like PT to stay in our immunization room for a full 30 minutes and remain seated during this time and to let the pharmacist know there are notes under her file of what happened with the first covid shot. I will now fill out a VAERs report and notified the mother I would being so as well and to call us if any further questions/concerns arise.