bullying in young kids

How do you teach your kids to react to bullying? My 3yr old comes home in tears because kids tell her they don't like her and aren't friends with her. She just tries so hard to be everyone's friend and she tells me "mommy it hurts my heart when they say that" 😢 I don't want to raise a suck but I also love how much she loves everyone. So far I'm just telling her if kids aren't being nice, go find someone else or something else to do. How do you guys react to things like this? Can't believe 3yr olds can be so mean already!!