That is a female Blue Tailed Skink......I have one that is probably 10" long......she has been coming back each year for at least 4 years......its amazing that she has survived that long considering how many creatures love to eat them......its no telling how many babies she has produced......and she is fat again......if you see one and stay very still they are Ant eating machines......I watched one on the edge of an Anthill......he pretty much cleaned out that Anthill
Other way around, if it was a blue tailed/ five lined skink, it would be a male. Females retain their white stripes and lose the juvenile blue tail. Males have the orange head.
Really impossible to tell apart from the Broadhead skink unless you catch them to observe closer, or come across a very large Broadhead.