Yes, get her to talk to the careers service, and probably to her tutor as well.
Usually, she would apply for MA places in her final year. That starts quite early - she should be thinking about it from the autumn of that last year, as funding is allocated pretty fast. It is not very easy to get a funded MA; she should try, though. Typically, to be competitive, she needs a first, though she will almost certainly get a place somewhere (not necessarily a funded one) with a 2:1. It is sensible to be aware of how much prestige the MA institution has, too.
Then, during her MA (in the autumn term, again), she would apply for PhD places. Again, funding is tight but not impossible. Again, she would usually need a distinction to secure funding, though not invariably; again, she ought to think of the prestige of the institution/course in question. A full-time MA usually takes a year.
During her PhD she would typically get some opportunity to teach, and would find out whether or not she enjoyed it. If she wants to be competitive for academic jobs post-PhD, she would also spend time publishing and networking and doing conferences. A full-time PhD takes 3-4 years.
Towards the end of a PhD, she would apply for postdoctoral jobs. These are typically short-term contracts, nine months on up to a couple of years. There are a small number of very prestigious and competitive ones that allow you to research for 2-3 years; these include little teaching but can help secure a permanent job, because the ideal is to publish.
It is usual in Arts/Humanities to clock up a few postdoc positions before getting a permanent lectureship, so you'd expect to be temporary for a few years. Lots of people decide during this stage to go into a different career, because there aren't many jobs and postdoc temporary jobs are very insecure and can be badly paid.
At the moment, starting pay for a lecturer isn't much off 40k, so it's not exactly true that lecturing is much worse paid than teaching - the issue is that, had you decided to become a teacher fresh out of university, you'd have had several years of promotions by the time you were the age of a junior lecturer. And I think teaching is less competitive to get into.