There are two ways to get informed of the real town where Yasma lives now.

1. Information about Clanegh -> Tavern in Clanegh -> Thoss
2. Direct information, that she lives in Thoss

I think the trigger of the tavern information is missing, so you got the information that she is living in Thoss now but no new entry -> Yasma Thinmarsdotter - Thoss

There is a possibility to get this information from another informant, so just go ahead in searching. But for sure it have to be fixed

Yasma is fixed in the german version, it seems the EN trigger has to be set seperately. I will reopen her bugreport, so it can be fixed in the EN universe too.

For some reasons you need to visit Jurge Torfinsson in Skjal first. After visiting and talking to him, Yasma is at home in Thoss.
Tested with version 1.13
Im not sure if this is a desired process or a quest issue.

I have to look up the quest triggers. I know that Jurges quest sets her queststate, but I don't know at the moment what else triggers her.