My grandma accused the housekeeper of stealing our passports?

Me and my mom are staying at my grandma's. My grandma is losing her memory so she has to have someone stay in the house with her. My mom and grandma hide the bag wih my and my moms passports really well so they flipped out and my grandma threatened to call the police on 'whoever stole it'...finally my mom and grandma found the bag in the big bedroom and the housekeeper (Rosa) started crying. She told my mom that sometimes in the middle of the night she demands that she looks for her makeup or glasses and starts shaking and she is afraid. She said that if she had called the police on her that she would have been deported back to Turkmenistan and it would take her a while to come back. Now she is threatening to leave and my uncle is coming over to settle the situation. I really like her and she is so nice to us. How can I convince her to stay????