What is the ruling on gold prepared for use, which is not devoid of the intention of saving, knowing that it is the woman's property from which she benefits when needed?

As long as a woman has acquired jewelry for adornment, there is no zakat (definition) due on it. It does not matter if she sells some of it for expenses, as that does not make it for storage. Rather, it is like someone who bought a car or clothes and then sold them out of necessity. The criterion is the original intent behind acquiring the jewelry, not incidental purposes.