If she isn't on all day and takes longer to reply, its less likely that she's agency ran. Some agencies may attempt to schedule some of their chatters so that their shifts don't overlap with the model streaming or when they would normally be asleep though.
If she does have pussy pictures or videos, I'd imagine that its locked behind a bigger paywall where she wants you to spend on more sessions before she shows it to you. I don't know if its the same with her, but I know a fairly big model that does that with her content. Most likely to limit the amount of people that would leak it, and pretty much eliminate the chance of a bot/stolen CC account coming in and purchasing a lot of content, then doing chargebacks and leaking. Of course, she may just not want to show her pussy and doesn't have that content.