Yeah, i know that feel. "Core" girls take forever to get anywhere, while you get thrown some dime a dozen one-shot fucktoys or at most some side characters with minimal development for quick sex distraction from the fact the main ones tend to get nowhere soon.
It does make sense in the context of incest games, where the family relation is supposed to be a major obstacle/taboo hurdle in the way - but there's a lot of games with little to no incest element where this format also rears its head out of familiarity & convenience, even though it makes much less sense, making things that much more frustrating i guess.
That said, things seem to have be advancing with Hailey & Alice already as of the cliffhanger. Let's see how it goes.
(As an unrelated aside, i'd say 0.39 was as much about setting up things for Pam to get in the way of the MC as for Rilley's general confusion and self-exploration on its own)