How can international student come to the Uk unis

There's a girl I know that would like to study Medicine in the UK preferably Birmingham . She is from an African country (Rwanda) she is in her final year of "A levels" , which is "examen d'etat" Shell get her results soon but she does not know how can she compare them to the A levels in the Uk , she is smart , she is studying BIology , chemistry , maths and English