Unsure if you thought about this in the longrun or not, but just in case you didn't, I'm hoping to get some sort of credit for this amazing idea(in the off chance you decide to impliment this)...
[SLIGHT SPOILER WARNING]
When you go back to see younger Scarlet and you two have "fun" in bed, and the options to pull out or do it inside are shown, if you decide to do it inside, what if the possibility of HEAVILY altering the timeline In the present occurs because you caused Scarlet to give birth sooner than the original Scarlet and the two redhead sisters have an older sibling because of the protagonist? I decided to pull out when I was given that option just because I was concerned I would ruin the timeline if I didn't. Just an idea concept for you to ponder(if you haven't already, also let it be known I'm not really a big fan of pregnancy nor have a fetish for that kind of stuff, but it WAS a good idea, just figured I'd reemphasize that for the story's sake)