Do disturbing dreams (nightmares) that a Muslim girl experiences, despite her prayers and supplications before sleep, signify something?

Good dreams are from Allah, and bad dreams are from Satan. So, whoever sees something he dislikes, let him spit lightly to his left three times and seek refuge with Allah from Satan, and let him not tell anyone about it. If he does that, it will not harm him. And whoever sees a good dream, let him rejoice in it and tell no one but those he loves. It is also recommended to recite Ayat al-Kursi before sleeping, to maintain the remembrances of sleep and ablution, and to recite the last verses of Surat al-Baqarah and the Mu'awwidhat (Surahs Al-Falaq and An-Nas), along with increasing acts of obedience, remembrance of Allah, and recitation of the Quran, and removing objectionable things from the house.