"For a mass as small as a human being, the Schwarzschild radius is of the order of 10-23 cm, much smaller than the nucleus of an atom; for a typical star such as the Sun, it is about 3 km (2 miles)."

So if she was compressed into a very small sphere, less than 10^23 cm smaller than an atom, she would have turned into a black hole. But if not, she wouldn't also possibly has mass of 800 micrograms, you might meant size of 800 micrometer? You can't just make matters or energy disappear, that just break the law of physics.