Timeline-wise, it might be easier for her to show up in Andor, if not this season, then maybe in season 2. The Mandalorian is about 19 years after we last saw her, and I want to see a lot of the intervening time. Like her dealings with Maul, taking the leadership of Crimson Dawn when he is gone, and dealing with the Empire, to just name a few.
That would make more sense. I think it's because she's a popular character and The Mandalorian is the flagship show. The rebellion working with or crossing paths with the underworld would certainly happen. Maul and Qi'ra making appearances could easily be worked in.