Did I do the right thing lying to my husband???

heres my situation: my mother in law lives in our apartment, he is the only son so she has always lived with him, and now that we are married she thinks she rules at home. She doesnt work because she is very obese and has osteoporosis etc. But she has gotten this idea inside my husbands head to open a restaurant, she used to work in a restaurant about 10 years ago! well it turns out my dad is selling his restaurant and my husband wants to get it and is already making plans for him & his mom, his mother is already puting in her ideas and plans etc.. as if it were hers! she can even stand on her feet for more than 1 hour! she thinks she's still young and thinks her ideas are better than anyones and feels like she is always right!!!grrr! I already have 2 jobs and if we were to open this restaurant i would finally quit one job so i could be there, and my mother-in law said "but you already have 2 jobs, you cant work"!!! Can you believe that!!! So anyways I called my dad and told him not to