I think that's what was implied, yes.
in the world setting Nobles can have Multiple wives and it never states if she Left or if she was basically just the Second wife due to Politics that kind of thing because even in OUR WORLD there were many times in human history in which Kings and other Nobles had MANY wives or married off their own Daughters to other Noble families in an attempt to make them Allies which Expands a families total Value to the Monarchy
Based on what was said and implied, I highly doubt she "left" willingly. More likely, she was taken out. She attempted a coup, essentially. She tried to out not only the other two wives but their CHILDREN. That wouldn't just be "forgiven" or wiped away. It's later stated by Volf's older brother that her family had to basically pay them back for her actions.
She likely didn't meet a kind end and it was just framed for the children (in this case, Volf, since he was young) that she just was "gone." Not to mention, based on what his older brother said, it seems like their father truly cared for his wife before he became a widow. It might not have been romantic love, it doesn't always have to be romantic, but he likely loved and cared for her enough if he's still visiting her grave EVERY MONTH for over a decade. I have family that I adored and I don't even visit them that often at their memorial.
can someone enlighten my why did wolf’s father 2nd wife’s left? is she the one who tried to assasinate the 1st and 3rd wife or smth?