Talking, shouting and kicking while sleeping

Patient: Dear doctor,My little sister is 12 years old. She is the youngest among us, 2 males and 4 females. Since ever she left my parents room and started sleeping in my room, when she turned 5 she would scream in her sleep. However, every year the screaming would get worse, it went from screaming 3-4 times to talking and saying things that i wouldn’t understand. Nowadays, she started kicking her bed and scream very loud. The weird part is that she doesn’t remember any of what she says or does when she wakes up and she denies what i tell her and get really surprised. I really don’t know if it is serious or not and i don’t know how to help her since we live in Saudi Arabia and in this county they don’t pay attention to such issues.I really want to know what are the causes for her case and how to treat them.Thank you,