Am I overreacting with MIL?

Me

My son has many allergies, especially with pet dander. My dear MIL is a full time RN but puppysits on the side. The rules when she comes to visit us to wash her hair shower and wear clothes we give her. She complains about having to wash hair and I caught her and my DH, her son, aka mommy’s boy, lying to me that the dog isn’t there. I told my husband he’s only hurting our son by lying bc she comes with dog hair and he flares up. I’m so over trying to protect my son from people who don’t care