Sore on chin

Hi my cat seems to have a small sore on the chin, is this something that will just go by itself, she doesn’t seem too bothered about it, pic attached

Hello!  Sometimes; it depends what is causing it and whether it becomes aggrevated by over-grooming, infection or a stream of saliva passing over it, for example.  A flea bite might often resolve quite easily, as might a small scuff or even a bacterial spot or inflamed follicle, but it's not guaranteed.  In particular there is something called an eosinophilic granuloma complex, which is an inflammatory reaction that can occur in that area; there are strawberry lumps, there are bite wounds, there are varous kinds of folliculitis.  If a 'spot' doesn't rapidly heal, you should show it to your vet because the more established inflammatory lesions become, the more difficult to deal with they can be.