i don't know I too scrolled too fast but we'rent they eating a meal together when the man in glasses inform the duke of the prince visit. I mean it was a different story if she's didn't hear it but if she did then I feel like it's just plain stupid and went off tracked from the og narrative where she's supposed to be a homebody and smart
I mean it's not unreasonable. The CP was due within the hour when she left so not a lot of time seemed to have passed since dinner. Also, she's likely sequestered in a specific part of the mansion away from the front so wouldn't expect the CP to show up and wander around to her area.
It reads like she went for a small walk to clear her head thinking he hadn't arrived, felt sick and overstayed on the terrace, and then CP finds her.

babe I'm on chap 18/19 I forgot but that was so stupid of her to go out alone like that even for just a breath of fresh air. she knew the prince was coming mmmmmm I thought she's smarter but we'll see