Hello Sharon and welcome to our message boards.
There is information on HPV transmission at http://www.ashastd.org/hpv/hpv_learn_dysplasia.cfm#2
Genital HPV is transmitted through direct skin to skin contact (genital to genital or genital to anal), and we are not aware there are any known risks of genital HPV infection being given to someone through saliva, or shared food and drink. There is no need for worry because you took a sip from your friend's glass.
With very few exceptions all women need regular screening for cervical cancer (such as Pap tests), and your friend's need for cervical cancer screening need not alter based on a shared drinking glass.
Hope this helps.