Thanks for the responses.
Yes, she is having the inspection done. And luckily since we are sort of in the line of work where we use this type of business, she is getting the visual inspection done for free and if they feel an air test needs to be done (which I'm sure it does) she will have to pay for that. We want to have sufficient evidence to present to the owner of the house. And my friend is willing to cover the cost of the air testing, for the health of her family.
Her older sister is going to take the blame for it. Her mom will not be as hard on her older sister like she would her. Plus her sister lives farther away from her.
I will update as things progress. The testing should be done early next week.