I had a couple ideas. One was that something would happen between the thieves and the knights (probably best if it didn't happen until after the next meeting between Crow and Penelope, so they'll be on slightly better terms)
Basically, I was thinking what could happen is this: Rikki leaves the camp at some point before her leg fully heals (I see her as the type to get wander lust, so she would probably just leave because she felt like it). While she's out, a patrol spots her and gives chase. One of the other thieves happens to be nearby and sees the knights closing in on her (could even be Crow). He would go to try to help her escape and end up being overpowered by the knights because there are too many of them. However, the knights wouldn't kill him because they want to interrogate him to find out where all of their stolen supplies are (the thieves had been stealing from them for months now, so they've lost quite a bit). Instead, they take him back to the camp.
I could see this going one of two way. If the prisoner is Alistair or Simon, Crow would be determined to go to the knights' camp to rescue him. He might also ask for Penelope's help. However, if Crow is taken captive, I could see Penelope feeling like she has to be the one to help him escape, even though she would be risking everything again.

My other idea is more for a private interaction between Crow and Penelope. I was thinking that some sort of accident could happen to either one of them and they end up stuck somewhere together. My main idea is that right after their next meeting, they see some knights walking towards them as they leave the tavern, so they run into the woods to hide, but get spotted anyway. The knights give chase to find out who they are, and one of them ends up twisting an ankle that leaves them unable to walk. I feel like it would make more sense if it happened to Penelope, because if Crow got injured, she could just help him back to the thieves' camp, but he can't bring her to the knights because they'll arrest him.

What do you think? We could do one or both or neither ^^
I'm also open to other suggestions if you don't like these

I'm going to bed in a couple minutes, so I'll get a reply done after my run tomorrow