"Many times I've heard adult children say, 'it felt like the rock that was my family […] my support network system that I grew up with […] was sucked into an earthquake fault'", says Carol Hughes, a marriage and family therapist based in southern California and the co-author of Home Will Never Be the Same Again: A Guide for Adult Children of Grey Divorce. "All of a sudden, their parents are divorcing, and they feel like the bottom has fallen out of their lives," she adds.

Reflecting on the memories shared with their family, adult children may wonder: "Was it all smoke and mirrors? Were they ever really happy?", Hughes says. Some of her clients have ended relationships and engagements because of their parents' divorce, or questioned their identity and self-esteem, she says. 

"A parental divorce can be a difficult experience for any individual […] no matter the age, no matter the marriage duration. The experience [or] transition is simply different," says Joleen Greenwood, a professor of sociology at Kutztown University of Pennsylvania, in the US. 

Adult children may for example feel obliged to help the parent they see as having "wronged" – for example siding with them, providing emotional and social support, or even supporting them with legal advice, she says. 

When Greenwood interviewed 40 adult children of divorce (ACD), a common theme that emerged was the feeling of being stuck between two sides: "Parents may see [their children] as peers, equals, or confidants and 'put them in the middle'," she says. "This is not saying that some parents do not do this with children under the age of 18, but it's more likely when the adult children are 18 or older." Daughters, in particular, are more likely to provide emotional support than sons, research shows.