forget everything you saw in tv and movies, as well as read in books of fiction. this is fantasy designed to entertain, not educate.
you want to become a witch? you just need to study. you don't need any lineage to become one. trace back far enough though and i'm sure you'll find some pagan religion in your genealogy. everyone does somewhere. Witch is a title, but basically, if you study, have a reverence for nature, and yes cast spells [though not everyone does] then you're a witch.
vampires on the other hand do not now, nor ever have existed. there is plenty of historic and scientific facts on vampires. the origin of the vampire myth isn't quite known, but it's a combination of historic figures, like Vlad the Impaler [aka Vlad Dracula] as well as medical conditions like polymorphic light eruption [basically a sun allergy] or porphyria. humans cannot be vampires, it's fantasy.
this being said, there are other options, for instance, while commonly you have to be born, i have heard about training to become a psi vampire. psi vampires drain energy, not blood. same people live life as sanguine vampires, they aren't real vampires, they just love them, so it's a subculture of people who dress and act like vampires. they even consume blood. they aren't real vampires, they are human, any one of them will tell you. [with a couple crazy exceptions] finally, they are real astrally. think of them like spirits, people can choose to study blood magick, and call upon vampires instead of deities. if your friend chooses to live life as a sanguine vampire, be sure she's safe about it, she should be tested regularly for diseases transmitted through blood, as well as the donor [if she has one] as well as be sure she doesn't ingest too much blood as you can get very sick. she could eat blood pudding to start with. [actual thing, made from cows blood, i eat it, not for everyone though]
point is for both of you, study all you can before deciding to become a 'witch' or 'vampire' since there's a lot to it, and it's a lot different than what you see on tv. as witches we cannot transform, levitate, fly, travel through time, shoot lasers from our fingers, and so on. we are more about study and balance than spell casting. our spells though use energy found in nature to help make our lives better. while magic is powerful, it cannot go against nature.