Potty trained child reverts back to peeing herself. Why?

My daughter is three. She is potty trained, but within the past week she has peed 5 outfits, and blown out in another. I can understand the blowout as she was sick, but her constant peeing herself has become an issue. We are putting her back in diapers because she keeps wetting herself. She has let us know when she needs to pee or poo and she has constantly been dry up until the past week. Im not sure what's going on. We have limited distractions for her such as movies with family and she still has peed herself. Its almost feels like she's being lazy. She's very capable. I dont want to say that she is lazy, but its very frustrating. She's my only child. We don't want to reward her when she pees herself but we do reward her with a treat when she uses the potty. She's earning back movies with each time she pees in the potty, but that tally goes right back up when she pees herself.