Ron and Hermione had 3 kids! Everyone forgets Victoire!
Here it is written in the book :
(Page 756 in the Deathly Hallows)
James had reappeared; he had divested himself of him truck,owl,and trolley, and was evidently bursting with news.
"teddy's back there," he said breathlessly, pointing back over his shoulder into the billowing clouds of steam. "Just seen him! And guess what he's doing? Snogging Victoire!"
He gazed up at the adults, evidently disappointed by the lack of reaction.
"Our Teddy! Teddy Lupin! Snogging our Victoire! Our cousin! And I asked Teddy what he was doing-"
"You interrupted them?" said Ginny. "You are so like Ron-"
"- and he said he'd come to see her off! And then he told me to go away. He's snogging her!" James added as though worried he had not made himself clear.
"Oh, it would be lovely if they got married!" whispered Lily ecstatically . "Teddy would really be part of the family then!"