How can i find out if i am part chinese?

there is a rumor in my family saying that my grandmother was part chinese, sadly she has ped away and i cannot ask her...that would have made my grandma chinese and irish...at different times in her life you could see that she looked like she could have some chinese in her and my grandma had four kids with my grandpa who was full irish but the kids at a young age looked like they could be part chinese but as they got older they just looked well white...lol...anyways my mom was the youngest and married our father who is moroccan so if i am part chinese it is very diluted yet when my older brother was born he looked very asian until he was probably two...so i don't know, myself and my younger sister never really had any resemblance of any asian race...is there any way of finding out?