There's a lot wrong with what you just said.

1. It's "Genus".

2. Homo is the genus, Sapiens is the species.

3. Taxonomy works in retrospect. We don't classify new species nor branches until they already exist. We can't simply predict.

4. A species is defined as a group that can interbreed and produce viable, fertile offspring. Mules for instance aren't a distinct species because they are largely infertile. This is why we classify in retrospect.

4.5. As a result it's impossible to know if Rogue would even constitute a new species. She would need to be capable of having children who can have children with each other. And I don't even want to get into how fucked up the implications of that are. It also means that if Rogue or her children could have viable offspring with ordinary humans, they cannot be different species.

5. Even if she was a whole new species, Rogue would probably not be an entirely separate Genus either. She would likely be Homo still. The split for her species wouldn't go that high up in taxonomy.

6. An organism is not only obligated to preserve its specific traits. It's obligated to preserve as many traits similar to its own as possible. This is why you'll see family groups in nature work together. Uncles and aunts will nurture their nieces and nephews because a substantial portion of their own genetics lives on in their siblings' progeny. They can still pass on some of their traits in that way.

6.5. This is why some people think gay people exist, from an evolutionary perspective. A tribe with 12 adults and 5 children is able to better provide for their collective kids than a tribe of 12 adults and 6 children. Some of the gay people's DNA is still in their nieces and nephews.

7. Sometimes you don't need to even share genetics with someone else. Completely unrelated cat moms will raise their litters together, because it raises their chance of survival overall.

This is all basic college biology. You should be able to find it fairly easily.