For a British audience it appears that the term should be trainee solicitor (articled clerk in older usage); Wikipedia describes this role in terms very similar to those in which you describe your friend:
The training and qualification required to enter the profession by being admitted as a solicitor is regulated by the Solicitors Regulation Authority. There are two graduate routes of entry into the profession. Prospective solicitors holding a qualifying law degree proceed to enroll with the Law Society as a student member and study the Legal Practice Course. Those holding a non-law degree but one which is a "qualifying degree" must in addition have completed a conversion course prior to enrolling on the Legal Practice Course. Once the Legal Practice Course has been completed, the prospective solicitor usually must then undertake two years' apprenticeship, known as a training contract, with a firm entitled to take trainee solicitors.
There is no real equivalent in the US, where “reading for the bar” (that is, serving an apprenticeship under a practicing attorney) has in all but a few states been superseded by earning a Juris Doctor (JD) from an accredited postgraduate law school, followed by passing the “bar examination” for the appropriate jurisdiction. Law school graduates are often employed by law firms in what amounts to a paralegal capacity while they study for the bar exam, so if your friend were applying for a position with a US law firm she should probably describe herself as a “Law graduate” (or JB or JD or whatever degree she holds) with n years of postgraduate paralegal experience.