"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(I might be getting carried away here, so feel free to ignore me if I start to be boring :-) ) the possessive forms are outdated in daily speech except for a few very specific nouns.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.