Does she really feel that she needs to go with a tour?
I left for my first round of travelling when I was 18 (for a 18 months from Europe to S. America). I went alone but was never really alone. There are so many other travellers out there, in the hostels. Unlike Americans many cultures travel extensively on their "gap year" so all-year every hostel usually has a few Aus, NZ, Uk kids on the "long haul".
Very often I would meet up and and travel for a few weeks with some people, then split up and travel on some more with different people. (Ahhh those days of freedom...) Not only was this a way to meet friends, it also allowed for more economical renting a car and lodging etc..
Though I have never tried it, many of my employees speak fondly of couch surfing (couchsurfing.com)