Don't fully click the padlock shut

You don't trust anyone, and whatever is going on here, you want to have an exit strategy. So instead of locking yourself in like instructed, you leave the padlock just before the click, so that it seems like it is locked, but in fact, it's not. Now you'll be able to remove your chains whenever you please.

You see your mother to your left testing her range of movement, now that she's locked herself in. She can turn around with a bit of wiggling, but the chains around her waist mean that there's absolutely no chance of her getting away from this mast. You gulp, and pray that she knows what she's doing.