Children from a previous marriage seem associated with the failures of second marriages, according to a 2002 study by the National Center for Health Statistics (part of the CDC in the USA), which collected information on marital failures.
Women who already have children at the time of remarriage are more likely to have their second marriage end in divorce than women who do not have any children. If the children were unwanted, the probability of the second marriage ending is even higher

. After 10 years of remarriage, the probability of that marriage ending is 32 percent for women with no children at remarriage; 40 percent for women with children (not unwanted); and 44% for women with children, any of whom were reported as unwanted. This is slightly higher for white women – 47 percent.
In addition, second marriages are more likely to fail for women under age 25 at remarriage than for women at least age 25 at remarriage – 47 percent versus 34 percent. Second marriages are also more likely to fail for women who did not grow up in a two-parent family than for women who did – 49 percent versus 33 percent. The probability of a second marriage failure is about 25 percent higher for women who have ever been forced to have intercourse, and women who have GAD (general anxiety disorder) are nearly 50 percent more likely to experience disruption of a second marriage than women who do not.