Does she go to Daycare? Who babysits her the most? Outside of you and your wife, who does your daughter get the most interaction with? If you ever figure it out, you definitely need to to cut them out of your lives, you don't need some racist teaching her how to become one as well.

I hope you made a big show of correcting her and teaching her differently.

Some adult who is clearly a racist.

She had to have learned it somewhere, if not from you, ask those closest to you. Sounds like you have a racist nearby.

Why didn’t you discipline the kid? Or leave? I would never tolerate that nonsense and would correct it quickly and even publicly.

Now imagine if she had said to her kid: “who told you to say that?!?!?” Kid: “you mom! Remember?” Yea that would’ve been even worse! Good thing you didn’t ask her how she learned that. Kids can be devils as well

Very young kids can make some really embarrassing 2+2= 5 observations. Before assuming it has anything to do with race, ask her why she thinks that. At 3 years old, she doesn't understand that people can have vastly different skin colours. Young kids often assume there is something wrong with the other child. When meeting a person of a different race for the first time it's very common for light skinned kids to think the darker skin is dirt. For dark skinned kids it's far more scary, because they often think the lighter skinned person has had their skin removed.

You're not born racist. It's taught

That’s not cool. You should have spanked her butt right there in front of everyone and took her home to bed without dinner. That should have been a memorable lesson for your daughter. That’s not how a young lady behaves! I can’t believe you just sat there and finished your meal! Be better parents!!

Your daughter wasn't lying and just proving what biology teaches: loving and preferring your own kind is the healthiest mentality.