Game of Thrones season 7: A traitor in the ranks of Daenerys?

In season 7 of Game of Thrones, Daenerys Targaryen has many allies at his side. But how many of them are really sincere? Who would be willing to betray her?

Daenerys has taken the lead since his debut in the series. From victim, she passed to the Queen of Dragons. Respected by her fellow men, she is the one who has the most allies (for now) to lead her to the Iron Throne. But the trend is likely to change! Already that his plan of attack towards the Lannister has just been annihilated by the fleet of Euron Greyjoy, it is possible that its allies also play with her. Oliva Tyrell, Ellaria Sand, Yara Greyjoy, Tyrion Lannister, Varys or Melisandre are people of power who come from the four corners of the kingdom with their personal stakes. Which of them would be able to betray the Queen of Dragons in season 7 of Game of Thrones? Rendez-vous next Monday to discover it on HBO and OCS simultaneously!
Lord Varys?

Varys got hot in the buttocks in episode 2 of Game of Thrones. The Queen began to have suspicions about her loyalty to her. But as usual, he managed to get away with a nice talk. In Stormborn, he swore fidelity to the Queen of Dragons but unfortunately for him his devotion will always be questioned. For betrayal is in its nature. You bet it will not take long before you turn your jacket over again. For whom else will he play the secret agent?
Tyrion Lannister?

In episode 2, Daenerys and Tyrion present to their allies the plan to bring down King’s Landing. Olivia Tyrell then takes Daenerys aside to warn her against Tyrion. Would the hand of the Queen of Dragons be able to betray her? It is doubtful whether Tyrion expressed the desire to sit on this throne, or even to avenge his family. Since the death of Tywin Lannister and Shae, Tyrion is no more than the shadow of himself and it is hoped that he will finally act in this seventh season!
Melisandre?

Who better than Melisander could betray the Queen of Dragons? As soon as she arrived at Dragonstone, she convinced Daenerys to meet Jon Snow. It is clear that the witch has some ideas behind her head and supports the King of the North despite having banished her from her kingdom.
Olenna Tyrell?

What if Olenna was the true traitor of Dragonstone? One wonders always who warned Euron Greyjoy of the position of the boat of Yara and Ellaria in episode 2 of the season 7 of Game of Thrones: would it Olenna? There is a good chance that the survivor Tyrell did not have the patience to wait until the Daenerys plan goes to the end. We all know that Oliva dreams of vengeance. Cersei killed his son and his two grandchildren in the Great Septuary. Maybe she was afraid that Daenerys’ plan would take too long and Cersei had the opportunity to run away. Let us not forget that Oliva organized the assassination of Joffrey: she is ready for anything!
In your opinion, which of the allies of Daenerys is likely to betray it?