Did I fuse

I'm a little kid alter I'm like four years old and and I remember when we were a little girl I would be by her and with her sometimes. I went to sleep for years and came back and now connected things with therapy and more things make sense. Whenever I show up now I feel like the both of us now like I'm half her and half me but still just me. And like I'm our inner child. I didn't want it to happen but I didn't not also want it to happen, or I never even thought about it until I felt it. Can it happen regardless and is that what fusing is?