I agree that it is annoying but all the incest tags on this site are already being used to label works depicting sexual relationships between non-blood relatives. I think it's too late to start making that distinction.
all family relationship tags (sister, mother, daughter, etc) have historically been used for blood and non-blood relations. including in-law, step-, foster, etc.
if you only want blood family, blacklist [inseki]. if you want non-blood family, include [inseki].
side note
the tag incest contains both blood and non-blood relationships, too.
@doarcutine I think this tag have many totally different means.Whether daughter is refer to the relationships or just refer to the biology. I think thats the start where we need to consider.
Taking what covert_peanut said into consideration, I think the tag should be described as "Works depicting incestuous relationships between a daughter and her parent or foster parent"