She needs to see a vet. Could be prolapse, or even a tumor protruding. Time for medical help.
I had one with a uterine prolapse in 2020, it didn't look quite like that, but it was tissue protruding from her. She required an emergency spay. With her it was quite noticeable she was in pain. We had trouble finding a vet at the time to do the surgery due to the pandemic, but the emergency vet gave us antibiotics, pain medication, instructions to do warm compresses to keep it moist and clean every few hours and to find a vet to do the surgery within a few days.
I had one with a uterine prolapse in 2020, it didn't look quite like that, but it was tissue protruding from her. She required an emergency spay. With her it was quite noticeable she was in pain. We had trouble finding a vet at the time to do the surgery due to the pandemic, but the emergency vet gave us antibiotics, pain medication, instructions to do warm compresses to keep it moist and clean every few hours and to find a vet to do the surgery within a few days.