Yup. My daughter went through that phase. We would be out in public and she would yell at people "My Mommy!" with a scowl on her face. I had to explain that no one was trying to take me

She is in daycare part-time, so you'd think she'd be used to sharing. Nope!
Keep doing what you're doing, she will stop eventually. Took about 3 months for my DD.