If it's just a dislocation then the longer it's left the less likely you are to getting this problem sorted because it will keep popping out again. Dislocated joints need popping back in straight away.
If it's a broken bone then if you leave it for any length of time it may start to set in the incorrect position leaving her unable to run away from danger.
If it's Mareks then you run the risk of it spreading to the rest of your flock and you could lose them all, if any recover from Mareks they become carriers.
Sorry to sound very blunt on this matter but as Springlands has said you have a duty of care to them (as with all animals) and failing to get the appropriate treatment is prolonging her agony.