During the Quiet Exit mission, Quiet has to speak in English to communicate to Pequod to guide the chopper to their location. Since quiet has the English strain of the vocal cord parasite she has to run away from snake once more. Since the parasite kills the host if they speak the correct language she is presumably dead in the desert since there is no way to stop the infection. So its canon that shes dead unless it is said otherwise by Konami which it has not been.
Some might say that since you can get her back than shes not dead. I would say that since you get her back from a mission that precedes the Quiet Exit, this quiet is not the same one but canonically shes still dead.

As mentioned in the last section, Quiet is known to have the English Vocal Cord Parasite. So being around here is very dangerous. If you were to say have s*x with her, she might moan an English word and then you both are *******. Another problem with the fact that she has the Parasite is her ability to express her feelings. Yes, she can make gestures and signs but the human language is the most powerful tool of communication that we have and not being able to talk to your partner makes relationships very hard.

Quiet shows her feeling only to Venom Snake, not the player directly. You might play as Snake but like the other snakes of MGS, Venom is their own individual in the story. She doesn't love you, she loves him. If she saw the stuff you were posting of her, she would do what she did to that one diamond dog solider but she would finish the job.

If you like MGS so much would you want disappoint Big Boss like this? Your a Diamond Dog, not a h*rny gamer. Have some dignity. Respect quiet like how Venom does. BIG BOSS IS WATCHING YOU.

To conclude, quiet does not love you, she has a dangerous parasite, and that she is most likely dead. So, can we stop being so obsessed with quiet? Shes only there to be an eye catcher. Don't fall for Kojima's Ruse. Be the soldier Big Boss would respect.