MIL advice

My MIL recently moved into our house. This isnt the first time that she has lived with us since we have been together the last 10 years. My husband and I own our house, we have a 3 year old girl, and are expecting twin girls in 8-10 weeks. I have recently learned that my MIL DOES NOT WASH HER HANDS, even after using the bathroom or smoking her cigarettes. I have expressed to her that she has to wash her hands because she is now in our home. Shes told me that she has eczema and washing her hands literally dries her hands out. So I went out and bought sensitive skin hand soap (that wouldnt cost me an arm and a leg, because Im also the only one working in the house right now) and some eczema lotion that she can apply after she washes her hands (this is also the same lotion that she told me years ago that she uses for her eczema when it gets bad so I know she CAN use it). I let her know what I did for her and told again the importance of washing her hands. She gave me a grin and told me, "I'm an adult. I do not need to wash my hands everytime or everytime I use the bathroom. I will not be washing my hands." I was baffled. I have expressed how it effects everyone in the home. I dont want anyone getting sick, especially my children. Its also setting an example for my children that I dont want created. She didnt and hasnt budged. I talked to my husband about it and he is on her side. He believes that because she is who she is, she shouldnt have to wash her hands unless she is wanting to hold the newborn twins after they arrive. Thats it. I am at a loss completely with what to do from here. I have resulted to spraying Lysol spray behind her, everywhere she goes because Im so serious about it. I dont even let her help with meals because I know she hasnt washed her hands. I dont think Im asking a lot from her and I feel I have given her compromises to fit both of our needs. Any thoughts or advice from other parents and/or grandparents?