She has been thinking about what brings it, what sends it away and how to hold onto it

Bristol Palin, the oldest daughter of former Alaska Gov. Sarah Palin and Todd Palin, was thinking about hope — what brings it, what sends it away, how to hold onto it — in the days after her parents’ split last week.

On Monday morning Bristol, 28, shared on her Instagram Story a sermon from a Texas pastor called “Abounding in Hope,” a reference to a line in the Bible.

Within hours, news reports spread that Todd had filed for divorce from Sarah, both 55, after 31 years of marriage.

Court records reviewed by PEOPLE show Todd filed last Friday, his birthday, citing “incompatibility of temperament between the parties such that they find it impossible to live together as husband and wife.” (Such language is reportedly not unlike citing “irreconcilable differences” in other divorces.)

Bristol Palin
Credit: Frederick M. Brown/Getty

Neither Bristol nor her parents have commented publicly on the pending divorce, though the timing of her Instagram post drew notice.

“When hope is present, people are encouraged to lay hold of what heaven has for them,” Christian Life Austin Pastor Rex Johnson says in the sermon, from March.

“Some have referred to hope as the ‘middle sister’ of faith and love,” he says. “I like that.”

Sarah and Todd, who met as high school students in Wasilla, Alaska and eloped in 1988, have five children together, including Bristol. Their youngest, 11-year-old son Trig, still lives at home. Todd is seeking joint custody.

Bristol Palin
Credit: Bristol Palin/ Instagram
Sarah Palin and Todd Palin
From left: Sarah and Todd Palin in 2010
| Credit: Kevin Mazur/Getty

Though they became famous as the first family of Alaska, the Palins remade themselves as TV personalities once Sarah left office. Bristol briefly appeared on Teen Mom OG last fall.

Divorce rumors were nothing new for the Palins. In the early years of their time in the national spotlight, they grew used to swatting them away.

“Our whole life is under a microscope,” Todd told PEOPLE in 2010.

Friend Dean Cain, who competed with Todd on a 2012 competition reality series, had dinner with them in Alaska a few months ago and said “they seemed wonderful together.”

“I’d hate to speculate on the cause,” Cain told PEOPLE. “What happens behind closed doors, and how people grow and change over time is something no one can ever predict or understand, save those two people.”