Women are mostly quite capable of orgasm, multiple times and varying lengths. BUT--It takes practice to really open the fountain, and a partner willing to make you feel like a goddess and take the time to build intimacy and communication. Women are also unique in what works for them. Stimulation of the clitoris, g-spots, etc remains only physical, the mental aspect is vital. Most important be willing to spend the time to make it happen. It will be worth it because the more orgasms she has the more she will want.
One note: After 20+ or even one that lasts for 20 minutes, there can be some pain and after tenderness from uterine contractions, but how many of us would care.
As a woman I love my ability to orgasm freely and easily, and yes it makes me extra horny.