I don't think that length is the best indicator of whether a gecko is a giant. Although most geckos will fit the lengths as outlined above, there are always exceptions as each and every gecko is different. A regrown tail or different proportions are some things that could factor in.
To me, a giant or super giant is an abnormally
large gecko that is at a
healthy weight. An small obese gecko, for example, cannot compare to a true giant. For this reason, both length, tail size, and weight should be considered.
Your female may be considered a giant depending on her weight. If she had a longer tail and was 9 inches for instance, she
might be a giant but her tail and weight should also be looked at. I have a 9 inch long female who maintains an appropriate weight of 70 grams but is no where near being a giant.
We just need to see pictures of your geckos and preferably weight to know for sure.