There is a some disagreement whether or not there really is a
form of 'female ejaculation'. Female ejaculation is believed to be
caused by a release of fluid from the Skene's glands. These glands
are located inside the urethra. The Skenes gland is similar to the
prostate gland in guys. It produces a fluid that is similar to the
chemical composition of prostatic fluid which is what makes up the
majority of semen. (Its possible that some urine may leak out
during sex from pressure on the bladder for some women. This is not
to say that ejaculation fluid is urine). When 'non-scientific' lab
tests were done on fluid produced from from the Skenes gland and
during female ejaculation, it was determined to not be urine at
all.
Some women may produce greater amounts of fluid from these glands
than others, which explains why some women seem to gush during an
orgasm while others many do not.
Remember, not all women will have the capability of ejaculating or
certainly not every time they have intercourse. It's not something
that takes place every time a female experiences an orgasm either,
so it does not reflect the quality or enjoyment of the sexual
experience.
The amount of fluid that flows out can go from a few drops to a few
tablespoonfuls. Stimulating a females G-Spot may be a way to help
her ejaculate.