Especially with Helen Copeland in the mix now and seeing her with Ian Ward, it makes me wonder if Mariah really is Sharon's daughter making her Cassie's twin sister? If this is the case and Mariah really is Cassie's twin stolen at birth then with Mariah already a part of the Newman family it will pretty much be solidified that Mariah will become a Newman in every sense of the word
Mariah if she does end up being a long-lost Newman then Nick will gain yet another daughter in Mariah and Sharon will have a piece of her daughter Cassie back because she will have Mariah and plus she has Noah and Faith
So then that is why I think they should just keep Summer's paternity as it is, by keeping her as an Abbott especially now that Phyllis is coming out of her coma or she will soon anyway and when that happens why change Summer's paternity from Abbott back to Newman especially with the new addition of Mariah into the Newman fold?