Kathleen Kennedy Townsend, the eldest child of Robert F. Kennedy, said in a Facebook post on Monday that the elder President George Bush told her that he planned to vote for Hillary Clinton. The former president, however, is not talking.

Ms. Townsend, 65, a former lieutenant governor of Maryland who on Facebook uses her middle name, Hartington, posted a picture of her shaking Mr. Bush’s hand.

“The President told me he’s voting for Hillary!!” the caption said.

Jim McGrath, a spokesman for the former president, 92, would neither confirm nor deny Ms. Townsend’s claim.

“The vote President Bush will cast as a private citizen in some 50 days will be just that: a private vote cast in some 50 days,” Mr. McGrath said in an email. “He is not commenting on the presidential race in the interim.”