About My Family 9/1

There are 5 people in my family. I have an older 1 sister and a old brother. I'm the youngest of of the three children. In fact, My parents got were divorced when I was 5 2 15. And now I'll will be 24 at on the 6th of this month. Now I live with my father and his new wife 3 mother. Because my father remarried other woman They were married after 2 years since after they got the divorced. Actually I have never met my real mother.  This is because  when she left and even I don't know where she is lives. Because At the same time my father told me like this warned me with something to this effect,

"You must not keep in touch with your mother no matter what happens.  , because She already is not no longer your mother. Ok Got it?"

That's how This is why I have n't never met her.   My new mother has a child who is a girl daughter from her previous marriage because she also got divorced her ex-husband. So there are actually 6 people in my family. In addition, we have 2 cats and one dog. They are so cute;  especially the cats! I really love cats because there were some cats in my house when I was born. Anyway I think it's hard for everyone some to get be married with someone even if you really they were in love at first.

Good flow of thoughts. 

1.  You cannot say "old" in this context.  This means that your sister and brother is really an old person physically.  I am sure you don't mean it literally.

2.  Must be a mistake or typo.  You mean you were five years old when they were divorced.  I can hardly imagine someone who does not know their own mother for their first 15 years of their life.  If this is the case, you must explain such an unusual circumstance.

3.  I don't know if you have accepted her as your mother.  So it is better to use wife.  If you use "mother", it implies you have accepted her as one.  If this is the case, you need to add something extra, "I live with my father and my new mother whom I had accepted her as one."