A funny thing

Yesterday, my elder sister found that her telephone was lost(she had lost her telephone),so she ran up to upstairs fastly(quickly) to look for the telephone,she, was lucky,she had found it, the telephone was rang at the moment , it(She was lucky she found it, the telephone rang just in time. It...) was Mother’s calling,my(calling. My...) sister said "Hi,mom." "Have you found your telephone?"the  Mom said eagerly,“Whom are you talking with now?"the (my) sister said amusingly (,amused.)."Oh...,I see." At last, we just looked at each other and laughed a hearty laugh...

"A funny thing

Yesterday,My older sister realized that her telephone was lost,so she ran up to upstairs quickly to look for the telephone and lucky for her the telephone rang, which helped her to find it.  It was her mother that had called. my sister said: "hi,mom! have you found your telephone?" the mom said eagerly: "who are you talking with now?" the sister said amusingly: "oh...i see”. We just looked at each other and laughed!

I corrected it so it sounds more like a native speaker was speaking this situation to a friend

A funny thing happened.

Yesterday my older sister realized her telephone was lost, so she ran upstairs to look for it. She was lucky she found it because it rang just then. It was our mother calling. My sister said, "Hi, Mom". "Have you found your telephone?" Mom asked eagerly. “Who are you talking to right now?" my sister asked amusingly. "Oh...I see,” said Mom. Then we just looked each other and laughed a hearty laugh...