Sally Morrison-Golden is the school gossip, the lead organizer of Rearden's fundraising auction, and the "richest woman Grace personally knew" (2.29). She has four children, the youngest of whom is named Djuna after her mother-in-law, Doris. That's not totally relevant, but we just truly do not understand how those names are connected, so we wanted to mention it. Sally is consumed with adding the most extravagant, outrageous items to the auction list, including a toe-shortening surgery and a spot in a $25,000 summer camp. She's also beside herself when the ridiculously wealthy Spensers don't make an appearance at the fundraiser that's being held in their home. Despite clearing their fundraising goal for the evening with room to spare, Sally gets wasted and won't stop talking about what a shame it is that the Spensers aren't there. She represents the social-climbing class of Rearden parents, in contrast with the more practical Grace.
Eva Reinhart is Frederich's second wife, whom he married after Grace's mother, Marjorie, died. Eva migrated from Austria and has two adult children of her own. While her marriage to Frederich technically makes her Grace's stepmother, their wedding took place after Grace was already out of the house and married Jonathan. Grace very maturely refers to Eva as her father's "new wife," despite the fact that Eva and Frederich have been married almost 18 years. Suffice it to say, Grace and Eva aren't very close. Most of the hostility in their relationship seems to come from Grace being upset that Eva cannot read her mind—she lets Henry eat cereal out of Grace's parents' wedding china, for crying out loud! There are a few other examples, but thankfully near the end of the book, Eva offers to let Grace store her old photographs at her second home on Long Island. She also gives Grace the wedding china, which she never knew Grace wanted.
Leo Holland is the fiddler next door who befriends Grace when she finally ventures out of the lake house. When they were kids, Leo and his brothers used to disturb Grace's mother's peace and quiet with their water sports and shenanigans. Grace completely forgot about this chapter of her life, but Leo hasn't forgotten her—he later fesses up that he saw Grace standing on the dock in a blue bikini when they were teenagers. This admission sounds mildly creepy, but it's pretty sweet in context. Leo's a Good Guy™, and he even sports the "crooked smile" requires of all slow-burn love interests. Unlike Jonathan, who kept Grace isolated from all of his friends and co-workers, Leo is thrilled to introduce Grace and Henry to his band members and encourages her to get involved in the community. In fact, Leo mostly seems to exist to provide a contrast to Jonathan and to help Grace begin to imagine a future without her crazy ex.