Daughters heartbreak

I have a almost 3 year old & when her father & I split, he’s not involved in her life, she always called every man daddy. So when I started dating my friend from high school she called him dad & stupidly I let it slide. Soon after she stopped calling every man daddy & just him. We ended up breaking up & the last two months shes gone back to calling every man daddy again my mom says it’s because she’s looking for a dad. Do you believe this to be true? I feel so heartbroken for her.