Why Arya hasn't arrive to Winterfell yet???

We're not even 100% sure she is headed there. Her reunion with Nymeria may have changed her mind.

She's not going to Winterfell anymore. Maybe that's why she's not there yet.

The scenes this season won't necessarily be on the same timeline. They showed Arya scenes last week and no Bran scenes to tease the audience thinking it was Arya at the gate. Arya arriving at Winterfell is as big as Jon meeting Dany, so they are making us wait just a bit longer.

I think she will be in Winterfell by the next episode.

She wasn't on this weeks episode...the next time we see her is the first opportunity the show will have to address this topic. A better posed question would be 'why wasn't Arya on this weeks episode?' The obvious answer would then be time constraints. I have read that next season the episodes might be feature length (1 1/2-2 hour) so that would be nice. Finally consider the fact that timelines on the show can be sketchy at best...characters covering vast distances within episodes where other characters storylines trudge on at a snails pace. Hope this helps.

The majority of the travels you just referred to were by sea, which is much faster than land travel in the pre-automobile era. And Bran traveled by land, but the distance between Winterfell and the Wall is much shorter than the distance between Winterfell and the other kingdoms of Westeros. Arya is going overland, and she had been heading south until she just recently changed her mind and decided to go north again. She would have been south of the Twins, as she had been going south after killing the Freys. It's a long way north, from south of the Twins. Unless you go by sea, which she isn't.

Frankly it would be much weirder if she HAD already arrived at Winterfell, significantly straining suspension of disbelief.