DEAR ABBY DEAR ABBY: My mother moved in with my sister in California around 1993. After 20 years, I asked her what she wanted to do with her storage unit, which was still in Arizona. Long story short, she said: “Clear it out. I don’t even know what’s in there. Take whatever you want, keep the pictures and give the rest to Goodwill.” My sisters have the same recollection. Over the next three or fou…