On one side it is not likely to be bottle jaw.
Bottle jaw is a swelling due to excessive fluid pooling, usually from a lack of protein in the blood, which is often due to fluke or johnes disease or occasionally a very bad worm infestation.
On one side, it could be something like an abscess or a tooth problem, or an infection of the bone. The vet will examine the swelling to decide the best course of action, which may be draining , removal of the tooth and/or antibiotics and antiinflammatories.
The vet will be able to advise you what, if any, wormer to use in your area and situation but it might well be worth doing in an old thin girl. Copper may or may not be needed, again your vet could do blood tests to check for deficiencies if you are not giving minerals or a lick. I would not recommend iron as anaemia in goats would usually be caused by a disease process, which should be addressed to help the anaemia. Iron may temporarily make an anaemic animal less so, if they lack iron, but it will be short lived unless the cause is fixed.