If You Were in My Side WHAT?

Few months ago I hired a new all around housemaid to work with us at home. At first she's okay but few weeks after she started answering me back every time I scolded her because of her mistakes. She will insist all the time that it's not her fault and blamed my 1 year and 11 months old child. Early in the morning this new housemaid is already sleepy and I caught her sleeping many times while sitting on the couch taking care of my baby. I am just staying at home mom so I know if what's going on with the housemaids inside the house. What I don't like now is she keep on having the same mistakes over and over regardless of the words I tell her. It seems she's becoming more stubborn as the time goes on and she keep on giving me problems. And few days ago I put a necklace on my son's neck and few days after I look for it if where is the necklace because I didn't see it anymore. When I asked her she said she don't know. When I heard what she said it's like my temperature directly raised to 90 degrees. How come she don't know that she's the one who look after my son? I know my son can't cut it even forcefully because it is thick enough. I was really mad. After I knew that thing there's another thing that made me really mad. My statue of Virgin de la Regla was broken and divided into pieces. OMG! again another negative factor from her. The worst thing there is she didn't admit that her carelessness was the one breaks my Virgen De La Regla statue. If you were in my side what will you do with this kind of housemaid? Keep or Fire?