Arriving at the playground on a beautiful day last summer, my daughter immediately noticed a little boy from the neighborhood who she played with frequently. She was thrilled that he was there so they could enjoy the park together.

As we approached the boy and his mom, we quickly discovered that he was crying. My daughter, being the nurturer that she is, grew very concerned. She started asking him why he was upset. The little boy didn’t respond.

Just as I was about to ask what was wrong, another little boy came running up and yelled, “I hit you because you are stupid and ugly!”

You see, the little boy who was crying had been born with a growth on the right side of his face. My daughter and I had talked about this earlier in the summer and I was stern in letting her know that we are not mean to people because they look or act different than us. She regularly engaged him in playing throughout the summer after our talk with no acknowledgment at all that something appeared different about him.

After this unfortunate encounter, the mother and her son left. My daughter gave him a quick hug and told him not to cry. It warmed my heart to see such a sweet gesture.

But as you can imagine, witnessing this encounter brought up a lot of questions in my daughter’s mind.

Not long after the little boy left, she asked me why the other boy’s mommy let him be mean. She realized that it was the exact opposite of what I had told her before. This was the moment I realized that I had to teach her not to run away from bullies. It’s my job as her mother to teach her how to shut bullies down so that she’s not in a situation where her confidence is eroded by another person’s actions.

While this situation was a direct confrontation, a preschooler’s mind is not always developed enough to notice when someone is subtly putting them down or not being nice.

As parents, sometimes we can feel so removed from our childhood experiences that it’s hard to remember what it was like to be bullied. In fact, I forgot that bullying could happen as early as preschool until I witnessed that unfortunate incident on the playground over the summer.

Bullying was never talked about when I was a kid. I wasn’t taught how to recognize or shut down a bully immediately. I wanted to do better by my daughter.

Another day, I watched my daughter get snubbed by a little girl in her class in favor of another friend.

It broke my heart to see it, but my daughter had no clue. She continued to try and join in on the fun. While that isn’t necessarily bullying, it reminded me that children can’t always decipher when someone isn’t being nice or fair to them in less obvious situations.

Later that night, my daughter brought up what had happened and told me she felt like the little girl was not being nice, just like the little boy in the park was not nice. Perhaps it took her a while to process what had happened, or she didn’t have the words to articulate in the moment that her feelings were hurt.

After both of these incidents, we had a discussion about standing up for yourself, but still being nice in the process. Of course, I had to put it in preschool terms. I told her if someone wasn’t being nice and it made her sad then she should tell them. I stressed that being mean back is not acceptable. I compared it to when she gets mad and yells at me (let’s be honest, every kid gets mad at their parents). I asked her if she would like it if I yelled back at her. She said, “No Mommy, that would hurt my feelings.”

At this age, I want to teach her to assume the best in other children. I want her to stand up for herself and tell them it’s not OK to make her feel sad. Learning to recognize when something hurts now and standing up for herself will build a solid foundation for how she handles escalated bullying as she gets older.

Not long after we discussed that it’s not OK for other children to make her feel sad, I witnessed my daughter tell a girl on the playground that pushing her down wasn’t nice. She looked her directly in the eye, as I taught her to do, and said: “Please don’t push me, it’s not nice!”

The situation immediately improved. I went from watching this other girl have the upper hand and ignoring my daughter to including her in the hide-and-seek game she was playing. Both girls had a blast!

I firmly believe that we teach people how to treat us. I also believe that bullying is a two-way street. As much as we never like to think of our children as the bullies, the truth is, it happens. It’s our responsibility as parents to teach our children how to treat other people. As I told my daughter to stand up for herself and let the other child know when they made her sad, it’s equally as important that she isn’t the one making another child sad. This is why I asked her how she would feel if I yelled back at her. If something would make her sad, then she shouldn’t do it to someone else.

Children model the behavior they see at home. As a woman, if I allow myself to be bullied by my husband, that’s the example I will be setting for my daughter. If I continually yell at my husband, then I am also showing her that it’s OK to be mean and bully other people. It starts with us as parents. Open a dialogue in your home with your children about what is and isn’t acceptable behavior to display or accept from others. Consciously make it a priority to set the example at home that you want your children to model in the world.

Monica Froese is a working mom who lives in Buffalo, New York, with her husband and 3-year-old daughter. She earned her MBA in 2010 and is currently a marketing director. She blogs at Redefining Mom, where she focuses on empowering other women who go back to work after having kids. You can find her on Twitter and Instagram where she shares interesting facts about being a working mom and on Facebook and Pinterest where she shares all her best resources for managing the working-mom life.