DM.. I want to clarify something that is wrong in your post.... Alea fired at the Beast that is near Sil and the arrow burst into flames... she then decided to aim at one of the large Shelnak Leaders that was bearing down upon her.. the Rock Swellers are all behind her in the passage opening being held.. for the moment.. by the two dwarfs... her arrow glowed when she took aim at the Shelnak Leader.. they are called that because they are the ones of their race with the most power.. and usually are at the head of the wedge they use to fight... she fired at that Shelnak and wounded him... her arrow piercing their invisible shield that usually keeps her arrows from doing any damage.
Now if you wish to change your action to the one you stated in your post to fire once more at the Beast... then you may.. but it will result in the same as last time.. her arrow bursting into flames... but if you leave it on the Shelnak leader before her then it will hit.
I have enclosed a map to help show where everyone is in relation to each other and their opponents.
Hmm hopefully I got this link right.. if the pic doesnt show let me know.
Also, to answer your question about the manacles... Sil is held by steel manacles.. old ones with some rust.. the chain is passed through a ring above her head keeping her arms up and her feet barely on the floor.
Any other questions.. let me know.
Edit: Trying pic again... let me know if it doesnt show still.