Gretchen Rubin’s “Happiness Project” is giving some readers indigestion. Rubin, daughter-in-law of former Treasury Secretary Robert Rubin, who helped kill derivative regulation, wrote a book and now gives advice on reaching contentment on AOL clips. After hearing Gretchen suggest people should “goof around with kids and read more,” Jill Brooke, whose play “What’s Eating You?” is launching in May, wrote on Facebook: “For Gretchen to be lecturing on happiness when her father-in-law made a Faustian bargain that helped wipe out the middle class is so disturbing. Goof around and read with kids is not easy to do when you’re juggling two jobs.” Brooke got inundated with calls and responses sharing or debating her annoyance. “On AOL [Rubin] said to ‘keep cash in the house, keep gas in the tank’ as a tip on how to have a ‘serene and organized home,’ ” wrote single mom Cathy Walker Meyer. “The majority of us are having a hard time keeping cash in the bank.” Brooke added that perhaps Rubin’s family should take their “hundreds of millions and create small businesses that employ people. That would be a happiness project that would spark praise instead of scorn.”