Star-crossed Clones

I decided to finish Never Let Me Go today, and I'm close to the end. Here's the scoop.
After leaving Hailsham, Kathy H. and her fellow students live in remote areas for a while - a farm called the Cottages, in Kathy's case - then became carers, looking after organ donors. After a couple of years of being carers, they start donating organs. They donate organs until they die.
Each student was a clone of someone, but they never get to meet their "originals".
After their friend Ruth dies, Kathy and Tommy begin a relationship. Tommy develops a theory, based on a rumour, that people from Hailsham can get deferrals of 3-4 years if they happen to fall in love with someone. But they have to prove they're in love. Tommy suspects this is why the mysterious woman called Madame took away the Hailsham students' artwork periodically; it will be used as evidence to determine if two donors are really compatible.
Kathy and Tommy (who has already begun his donations) find Madame's home and ask her if the rumour about deferrals is true. She refuses to answer their question, but she allows them to speak with their old headmistress, Miss Emily. Miss Emily informs them that the rumour is an old one that seems to spring up out of nowhere every few years, a shred of hope for donors to cling to - and nothing more. Then she proceeds to tell them why she and Madame really collected their artwork for all those years...

That's where I'm at.