One important point is that she shows up to the beach with Darryl regardless, i believe going to the beach is an event that always happens for her, i suspect even if we don't go to the beach with the girls she still accepts Darryl's invite, the next update/chapter might make this clear.
If you are on her path there are subtle changes to show she's more interested in what the MC is doing and a bit more annoyed by Darryl's antics than if you aren't messing around with her.
I interpret this as, if you are on her path she's way more into the MC than Darryl, but she's still shopping around and weighting her options.
She didn't know the MC would be at the beach with Alexis, Erynn, Iris... she couldn't have been planning to make him jealous, she accepted Darryl's invitation to "try him out".
I don't think he's gonna get it, even on a non-Val playthrough, dude is a creep afterall, but i can only interpret her accepting Darryl's invite as shopping around.
Keep in mind that back in training camp she says Darryl is one of the guys on the team she would fuck, she says the MCs name too if you are collecting her points, but Darryl is always an option for her.