Ash had already put together a couple of countermeasures just incase there was any sudden betrayal.
There was little reason for her to put her full trust in anyone especially when it involved that kind of influence where people had even less reasons to keep their word or promises.
Sometimes things like their word or promises were completely worthless since not everyone was so honorable to keep them.
What nobody was aware of was that she had already prepared for such a variable whether she would not be let by the group or would encounter trouble getting back out.
If there was a need to escape then there was more than one escape route that had been prepared and only she knew where they were.
All that was needed was for her to make use of them if anything were to go wrong.