Was it necessary? How do you even know if the piece doesn't mention it?
The fact that they were "partners" was mentioned in an earlier article about this story. Look at this interesting piece of the story.....
The GIRL was well-fed and hadn't had to spend time in the closet, police said. Jenkins — whom the children were ordered to call "Dad" — disciplined the children, police said, while Rowles took a more passive role.
emphasis mine.
The above quote sheds light on why the fact that they were lesbians and male haters is an issue here.