Squirting or a female ejaculation is very rare, not because its hard for a woman to do, but because so few women are aware of this type or orgasm.

Let's cover what goes into her "juices" first, which are glucose, prostatic acid phosphatase, urea and creatinine. It's 100% sterile so you don't need to worry about getting any on you, and yes the last two ingredients are commonly found in urine, but again these two elements make her "squirt" sterile which can be a few drops or a orgasmic shower.

With proper G-spot Stimulation this spongy tissue fills with fluid, for some women her "Squirt" seems to come from her urethra (like urine) and/or nearby Skene's Gland. Further the sensation is such that women who can ejaculate often hold back, thinking that they need to pee.

Keep in mind some women are afraid of or never had a female ejaculation, so if she is unable to cum, just keep trying once in a while and don't worry about it if she can't.

Remember many women are skittish about squirting as they don't understand it, the best way is to explore this in the shower where clean up is easy. Men, be supportive and understanding as you help them explore their sexuality. Women, trust in you man to except every part of you (If he can't go out and get a real man).