I am Puerto Rican

Some snippets of conversations about race/appearances at the homeless shelter where I am volunteering

Conversation between Bryanna, a Puerto Rican-white mix and Skyye, a black-white mix after Bryanna sees Skyye's mum:
B: How come you're Puerto Rican when your mum is black?
S: I'm not Puerto Rican. I'm mixed.
B: No you're not! You're Puerto Rican!

Then Sally, a Puerto Rican mother of four kids-- two who look hispanic, one who looks white, and one who looks black but without the nappy hair replies:
"I'm Puerto Rican and so is she and she" (as she points to the girl that looks white and the girl that looks more black).

Then I ask the kids: So what do you think I am?
Kids: You're Puerto Rican. And if you're not Puerto Rican, you're white.
Me: No, I'm Chinese.
Kids: No you're not! You're Puerto Rican!
(This happens numerous numerous times)

Apparently my very white friend who taught kindergarden in the past encountered similar difficulties with explaining his race.
Kids: What are you?
White Guy: I'm white.
Kids: So are you African American or Jamaican American?

*In general, the kids are a bit confused too. Devin (white), Olivia (Filipino), and I (Chinese) are all volunteering and we're known as the "sisters". We told them we're sisters because we're all part of God's family, but I think they still believe that we're biologically related even though we told them that we don't have the same parents.

Sean says to Olivia: You and that other girl (aka me) look alike but you and Devin don't look alike.
Sean (after two minutes of staring): Actually, you two do kind of look alike.