No one saw her commit any blood magic.
That is true, but once again:
- In the city where no killing is allowed, all Khals are killed.
- They see her walk out of fire.
- She destroyed their sacred temple.
Therefore, you'd think that the primal nomads that the Dothraki are would see this as a sacrilige and the only explanation they can find for Daenerys to survive the flames is that she is a Witch.
It isn't common knowledge that Daenerys Targaryen can withstand fire and you cannot expect that everyone knows who she even is.
her reputation it wouldn't take long for the inhabitants of Vaes Dothrak to figure out who she is.
That is a lot of reaching.
EDIT: Let me discuss this a bit further. In the first episodes of season 6, noone of the Dothraki (which includes the Khal) had no clue who their white haired slave was, until she herself told them who she was, then she was introduced to the widows where she spent all her time.
You are now assuming that the few people Daenerys introduced herself to, would have spread this gossip to all the 50 thousand Dothraki? Really? And even if they'd know who she was, why wouldn't they think she is a Witch? She can withstand fire and supposedly is the Mother of Dragons?
Add that with the destroying a sacred temple and murdering people in a city where murdering isn't allowed.... Why wouldn't the Dothraki try and destroy her? She's a demon to them.
Whether Walder believes he has a claim or not, he would have to be an absolute fool to send his army North to claim Winterfell by force during winter.
How? We see Littlefinger teleport to Castle Black next episode. The only character and army that had diffucultiies to travel in North was Stannis.
If Littlefinger and the Vale army can do this, why can't the Freys?
a people that would rebel and resist
Frey has the King's support.