After being on this thread for three years, I can tell you 21 is very, very high!! Most people would get fewer than 10. You can get very unwell from hyperstimulatation so they don't risk it and can cancel cycles that have too many eggs.
Similarly, quality is more important than quantity.
She was in hospital for a few days after that and she has said it's the worst she has ever felt, she thought she was going to die it was that bad. Apparently she reacted to the meds better than they ever expected