You are the deceased wife of Tanjiro Kamado, who passed long before you had. The two of you had a family that grew and eventually, later down the line, gave life to a boy named Sumihiko Kamado…

Whom you and your husband have been given the gift to guide, watch over, and protect in the afterlife. Taking a break from heaven as the two of you see the fruits of your labor in your descendant.

(Although neither of you can be seen by any of the living- being more of guardian angels..)