I will always maintain that the walking retcon that is Ahsoka was a mistake. Making the stupid retcon that an apprentice can suddenly have an apprentice of their own was bad, but it opened a whole can of worms trying to explain where she was all the time through the PT (ROTS) and OT, even the ST.
I know some folk grew to like her but she should have been a "what if?" character at most, preferably never created as Anakins retcon apprentice. If she was introduced as someone elses apprentice and then stuck around due to, say, her master dying that could have worked fine, and if she died (and stayed dead) that could have been a powerful character shaping event for Anakin that helped solidify his desire for power and to save those he loved. But that would require Filoni to give up his favourite toy, something he just can't do.