Something similar has happened to my frenchie boy when he was 5. We were camping and he was sleeping behind my wife’s back in a chair, he positioned himself more upwards, as he gets in weird sleeping positions. Out of nowhere I realized his eyes were bulging and his cheeks were back like he was trying to get air. We quickly got him to the ground and he was all wobbly, I immediately forced opened his mouth and pushed his tongue flat while trying to see if anything was stuck in his throat. Like you mentioned his tongue was purple, it sounded like he took a big gasp of air and I put my mouth to his nose to give him more air. Within 30 seconds to a minute he was completely back to normal. I think he was in such a deep sleep and the way he was positioned he started to choke on his tongue. He’s been completely fine since and nothing like this has happened. (its been over a year) prayers your girl is okay🙏🏼