My mother.

This is my mother. She works in a school, she's a teacher.
She's from Campo Magro, but she lives in Colombo with her husband, my father. She starts working at eight o'clock and finishes at six o'clock. In her free time she goes to the house of her brothers. Sometimes she goes to study with colleague.

My mother.

This is my mother. She works in a school, she`s a teacher.
She`s from Campo Magro, but she lives in Colombo with her husband, my father. She`s starts work at eight o`clock and finishes at six o`clock. In her free time she goes to her brothers' house. Sometimes she goes to study with colleagues.

My mother.

Allow me to tell you about my mother. She`s originally from Campo Magro, but now she lives in Colombo with my father. She's a school teacher, and starts work at eight o`clock a.m. and finishes at six o`clock p.m. In her free time she often goes to / visits her brother's house. Sometimes, however, she goes to study with a colleague / colleagues instead.

Good job! You used very concise sentences and I understood everything that you wanted to tell me as the reader. As your vocabulary improves and increases, I am certain you will compose better sentences. As to the English, other than as dialogue in a novel or play, or you showing me a picture of your mother, or her appearing in front of me, one would never write or say, "This is my mother." I really do not recall seeing it in text like this as a stand alone sentence. Grammatically, it is correct, but as written text, it simply does not tell me anything. Understand? It is assumed, it is more natural, that your mother's husband is your father, so no need to tell us that. On the other hand, if he were not, you should mention that since it is unusual and we would not know that. Understand? I used "starts work" instead of "starts working" in the sense of that is when she arrives, not when she actually works. Perhaps a nuance or expression particular to American English, but that's how I speak as a native speaker.  I rearranged and rewrote a sentence or two to make them all "flow" together more logically, easier to read, and to  provide contrast among the last two sentences as I felt you intended. My apologies, however, if I misinterpreted or misunderstood. Keep writing and keep posting! J.

My mother.

This is my mother. She works in a school, she's a teacher.
She's from Campo Magro, but she lives  in Colombo with her husband, my father. She starts working at eight o'clock and finishes at six o'clock. In her free time she goes to the house of her brothers. Sometimes she goes to study with a colleague.