Honestly, I'm not sure there is... it sounds like you and Milu are overbonded, and now she has separation anxiety. That is the way that I would treat it. When she's at your dad's practice leaving for a minute, then five, then fifteen, etc. It's better for her to be a little more independent. It will help her confidence, and will give you more options if you ever need to go somewhere you can't bring a dog.
