I have finally found a collar that fits my girls!!
I have been searching for months now for collars that would fit my girls, all have been waay too big for them as they have quite petite necks. Turns out I didn't need to be looking on any pet websites or searching every pet store for a collar that is around 4/5 inches at it's smallest and finally I've come across some, good 'ol Walmart! Their kitten collars have worked perfectly for my girls! Now I just need to find a good harness that they can't wiggle out of!