"My cousin will hear about this."
Translation:בת דודה שלי תשמע על זה!
Yes, if you are interested (I might be getting carried away here, so feel free to ignore me if I start to be boring :-) ) the possessive forms are outdated in daily speech except for a few very specific nouns. For some reason people do say אחי, אחותי, תורי, and maybe a few others, but almost never do it with any other word. It is formally correct though.
its definitely interesting. I'm familiar with how often אחי is used in conversational hebrew, it's like "bro"
Yes, and sometimes also אחותי. But I would also say אחותי עובדת שם, my sister works there. Although I would never say אמי עובדת שם, my mother works there, I would say: אמא שלי עובדת שם. I don't know why!