I see, her bladder had reached her absolute limit! I guess Mr kidnapper guy did end up pushing her bladder to the limit like he wanted - even though he was captured in the end.
I can say, it's just I wasn't sure if you actually wanted an answer. Well, there was no "holding it" for longer, that and the next page was it, whether she wanted or not, she was going to pee then (and she really didn't)
I can relate to this! Answering questions about your stories or whatever can feel like you're robbing people of whatever scenario they had imagined. I'd like to hear what would have happened, but it's up to you.