“Expecting a child” is necessary in order to make it clear we aren’t talking about adoption. And I think a reference to there being no father instead of merely a lack of parental involvement in conception is necessary in order for more casual fans to catch the link with Anakin/Vader.

I understand you’re trying to paint her parents under a more sympathetic light so that their abandonment of Rey is more due to the fault of her own nature and their fear of it. But I genuinely don’t think Rey should be that threatening at this age as a creation of the Force. We have Episode 1 Anakin to look to, and he didn’t appear to have a speck of evil in him (except for beating up Greedo in that deleted scene). Besides, the implication you’re making here is that they are also Force-sensitive enough to realize the dark potential Rey has. This is a big no-no in my opinion, as they need to remain as normal and worthless as TLJ portrays them.

I’m currently going for the concept that if an extremely powerful Force user tries to grow in their power, the strength of their light scales with the shadow it casts. Essentially, you start unlocking your true potential, but as a result there are exponentially more temptations to turn to evil and use the “quick and easy” path. Obviously Rey as a child isn’t even aware of the Force; her power is still (mostly) latent. Therefore, we have to assume that the only thing that could scare her parents enough to abandon her is the fact that her mother never had the prerequisite relations for such a thing to even be possible. Perhaps she does exhibit some slight Force powers, which some people in the Star Wars galaxy would see as evil no matter what, which leads to her abandonment at a later age than birth.