It's pronounced "Sen".

"And if a woman should say she doesn’t want to have children at all, the world is apt to go decidedly peculiar: ‘Ooooh, don’t speak too soon,’ it will say - as if knowing whether or not you’re the kind of person who desires to make a whole other human being in your guts, out of sex and food, then have the rest of your life revolve around its welfare, is a breezy, ‘Hey - whevs’ decision. Like electing to have a picnic on an unexpectedly sunny day or changing the background picture on your desktop. ‘When you meet the right man, you’ll change your mind, dear,’ the world will say, with an odd, aggressive smugness."