First off, it's rather hard to sympathize with someone who had to be told after the fact that Mike had used food coloring to get his face the desired shade of green because she's too stupid to be able to tell the difference between it and makeup. As Robert Reed would have said when he deconstructed the stupider episodes of The Brady Bunch, Elly has the option of either being a congenital idiot, being blind drunk or needing eyeglasses. What's more, she used soap and water and just gave up because it never occurred to her to either read the notes on how to clean the stuff off that come with the package of food dye or consult a guidebook on how to remove the stuff. White vinegar and baking soda applied to Mike's face would have shifted the dye and kept him from getting sick using a dirty school soap dispenser but she insists on not learning that because we put vinegar on fries, not on faces.
In short, we have a typical Sudden Unintelligence Incident from the master of spineless idiot martyrdom and pea-brained sloth. We'll have another one later in the year when it still doesn't occur to her that people aren't going to want to help her out if she can't manage to be grateful despite their not doing it her mother's way.