The chiro should be able to do some specific measurements to see if the leg is truly anatomically short or if it is a really stubborn functional deficiency. If it is truly anatomically short, my opinion is that some sort of lift is very appropriate. I like to have the shoe on that side built up by a professional. If it is functional, the water is a little muddier. A heel lift may be appropriate short-term IF you are working on the underlying cause in the meantime.