Seriously, no one ever doesn't want food. Family meals. Midnight snacks. Costco cookies. Pizza gift card. Whatever.
Or a book where the character has the kid's name, if the name is common enough to find one (or you can get them made). Maybe I'll still think that is cute by kid #4, but kid #1 cured me of appreciating blankets. Practical stuff like diapers and wipes (if they're not doing cloth) is also always appreciated, and anything to keep the older ones busy (craft stuff? old movies from your kids?).
I know with my second boy I was really excited when people gave him keepsake or personlized stuff so that he had a few special outfits and mememtos of his own. I had all the basics that we needed by then, so things like monogrammed bibs or burp cloths, a piggy bank, a personalized blanket, an engraved picture frame, etc. were my favorite gifts. And I always love getting books, especially if you can find one that, like token suggests, includes the kid's name, or one that is signed by the author or inscribed with a special message to the child.
The family is über rich, and she's a SAHM with a nanny, so it's extra difficult because they can buy/do just about anything. The nanny also is an amazing cook!
I will definitely look for something personalized. They like 'younique' names so it'll have to be Engraved/monogrammed.