being careful of one's speech

Q: A 15-year-old adult girl was misbehaving with her mother. The mother said to her (in Urdu), “Allah Ta'ala is watching you”. The daughter replied in a sarcastic tone (in Urdu), “Well! Allah Ta'ala is watching me! (Urdu: Acha! Allah mian mujhey daikh rahay hain!). Then the mother said (in Urdu): “Allah Ta'ala is listening”. The daughter replied again in a sarcastic tone (in Urdu): “Well! Allah Ta'ala is listening to me! (Urdu: Acha! Allah mian sun rahay hain!). The question is: is the ‘eman of this girl valid after saying these sentences? If the 'eman is invalid after saying these sentences, what is she supposed to do to revive her ‘eman? What about her salats, fardh Hajj, fardh fasting, etc.?

Q: I'm writing in regards to a conversation happened between myself and my husband today. We were listening to a hadith which says that if a Muslim calls another muslim kafir but the other Muslim is not kaafir, then the one who make such accusation committed kufr and become a kafir. My husband asked me to explain this and I said that one Muslim should not accuse another Muslim that he/she is kafir as this a very serious matter. When I said that, my husband replied that: Oh, you said that to me as well. When I asked him that when did I say something like this, he said when you are angry you don't know what you say in anger. I then become very worried and asked him again that pleases tell me exactly when did this happened as I do not remembered this. Then he said, I don't know. I don't remember. I later asked him that why did he say this? He again replied that he just said it and he doesn't know why he said it. After that I was really upset thinking that does he believe that and that's why he said it or did I say in the past and don't remember, but the more I thought about it I became more and more worried as I couldn't recall this. When I asked my husband again and again that pleases if you remember this then please tell me the truth so I can ask for help and guidance, but then he said that he just said and he truly doesn't remembered anything. He also said that he is willing to swear on the Holy Quran that I did not say anything to him like this. As far as I can say that i'm very confused and not sure what to think or believe my heart tells me that I could never say anything like this but my mind is not with me. I'm truly confused. kindly please help me in this matter as I'm very very worried and upset. I have two children and they are young, I tried all my life to be a good and practical Muslim. I always pray after namaz that I stay on the right path. I ask only Allah Ta'ala for forgiveness and guidance.