In Chinese culture, we believe that a dead soul would come back to home on the seventh day after death. I wonder if my grandma will come back on her seventh day. However, she didn't come?

When we felt disappointed, we encountered a fantastic thing after four days after my grandma's seventh day. There was a beautiful bird standing on an airer on our balcony in front of the windows. It is said that a dead soul could attach inside animals and insects if he/she wants to see his/her family members. So, I wonder if my grandma came back. But the number "four" symbolizes "death". So, I wonder if my grandma didn't want us to miss her so much because she's dead already.