So far it hasn't been a problem on either route - it just seems to be a matter of a scene option here and there right now. For Carol, there are other ways to get under Abigail's skin and get her off of Carol's back if you choose to help Rachel and you get a wilder Rachel scene in the latest release, but things up to that point were otherwise similar - different dialogues, some more drama with the husband early on that makes the help more necessary, but the story advances with both ladies either way. Likewise, Rachel still gets where she needs to be if you help Carol, but there seems to be less drama about it.
But, that's also a good reason to do a split when you have to choose: you get to experience all of the consequences, and all of the benefits, of both choices.
You simply can't have it all in a single run without employing big-time cheats, and as Sancho always says, that's a good way to break your play through.