My mother thinks that my sister is infected with evil eye so she was using an egg to get rid of the evil eye. Is it shirk?

My sister has been experiencing signs of evil eye so my mother used a raw egg to wave around my whole sisters body while reciting some dua or the 4 kuls (I'm not sure what exactly she said). I found this extremely weird and sketchy but I couldn't stop her no matter how hard I tried. Later, she went outside and threw it on the ground and said some birds will come eat it. I'm very confused on what she did and if its shirk or not. Please tell me ! Thank you.