BTW, do we interpret “…and then will return Vallow Daybell after that trial to serve her time in Idaho” to mean that if found guilty of the AZ crimes, she will serve whatever sentence she gets in Idaho?
"...to mean that if found guilty of the AZ crimes, she will serve whatever sentence she gets in Idaho?"
No.
The wording you are citing is the article's paraphrase of the extradition document, but the confusion is more from the article than the doc itself, a doc which also includes relevant portions of AZ law, as well as the ID response to the request. How it will work:
1 LVD will serve the Idaho sentence first before she serves any time in AZ. ID time is served in ID, although she will be in AZ for a trial temporarily, before being returned to ID to resume serving it once the trial in AZ is over.
2 IF CONVICTED in AZ, she serves any added time in AZ, but she has to finish her sentence in ID first.
... Since the ID sentence is multiple LWOP terms to be served one after another, her sentence in ID can never be completed. So, at least as things stand now, she can never become available to serve any time in AZ.
... But there is always the theoretical possibility (very unlikely, however) of some appeal ending or shortening her ID sentence, making her available to serve time in AZ.
3 There is also another scenario in which her AZ sentence would be served FIRST, which would be if she is convicted and given the death penalty. So far we have not seen an indictment made public with that possibility, but if charged with the MURDER of CV (rather than just the conspiracy to commit), that would then become a possibility.
4 The document provides that she can now be moved freely from ID to AZ, and back, to whatever degree is necessary, as many times as necessary, with no further decision or document required.