Ihave herpes, and my 4 yr old sister had drank out of my cup, can she contract it?

No risk: If you have genital herpes, it cannot be transmitted except by sex with another person. No exceptions, no worries. If you have oral herpes, it can be transmitted by kissing or performing oral sex when you have an outbreak, or sometimes even if no outbreak is present. However, the virus is rarely if ever transmitted by shared drinking glasses or cups, utensils, etc.