MIL smoking

My husband’s family is visiting for the week and they’re staying with us, his mother smokes pretty heavily. I have a 10 week old and a 2 year old and my house is absolutely smoke free. She goes outside to smoke but the smell sticks to her. I won’t let her hold the baby if she doesn’t change her clothes and throughly wash her hands but the smell gives me a constant headache. I cannot stand it. She’s sleeping on an air mattress in the kids room (we moved the kids to our room) and her luggage has made their room smell completely like cigarettes. I take pride in my home, keeping it clean and smelling good. Hopefully the smell doesn’t stick around after they leave 🙃