The latest news article I can find about her is this one from last summer:
34 year-old Leannah Gardipe appeared in Missoula District Court on Tuesday.
newstalkkgvo.com
I'm guessing her case is still making its way through all the pretrial hearings and motions and all that. In the story above too, that lady killed her kids in 2019 and the actual trial didn't start until last month.
The pandemic really seemed to slow the process down a lot; but even before then, prosecuting really serious crimes has always been a painfully slow process.