My friends male Persian cat wont mate with my female Persian cat?

A friend of mine gave him his 2 year,3 months old cat to mate with my female 2 years,8 months cat. They're both pure Persian cats and are registered Pedigrees. The male cat although younger, is bigger in size. They've been together for a week now. I know the female should go to the male's house and not the other way round but that was not possible. My female cat is in heat and is obviously interested in him, however; he is quite shy and rarely approaches her except to sniff her behind. I would adopt kittens instead but where i live, there aren't any shelters to adopt from. We've already discussed the possible scenarios if my cat gets pregnant and are ready for whatever number of kittens that may arrive. How do I entice the male cat and encourage him to mate with the female cat? And is them staying together for a week but not mating, normal?