Maybe Hansel and Gretel's stepmother had it right when she sent the kids off into the woods in an attempt to abandon them. Okay, maybe not, but there's no denying that getting along with a stepchild isn't always easy. An unruly stepchild can also turn a new marriage in to a matrimonial endurance test. So how can you take on your new parental role without losing your marriage or becoming the clichéd evil stepmother or stepfather?

Your new younger family member doesn't necessarily have to be a wild child who’s prone to temper tantrums or a teen who’s into drugs to have a nightmare on your hands. "The most common situation you’ll face is step kids who undermine their stepparents," says Dr. Susan Bartell, psychologist and contributing expert to stepfamily website bonusfamilies.com. "They’ll often refuse to listen or obey rules," adding that it can cause a deep rift between a couple.

That’s what happened to Valerie Coleman, compiler of and contributor to Blended Families: An Anthology. Coleman spent years being undermined by her stepdaughter, who was 8 years old when Valerie first joined the family: "[She] told her mother that I didn’t let her spend quality time alone with her father when she came to visit. So I went to my room when the kids came to visit," says Valerie. "Our daughter then complained to her mother that I didn’t want to be bothered with her because I went to my room." Valerie felt like there was nothing she could do to please her stepdaughter.

Valerie had three children from a previous marriage, and her husband had a son in addition to his daughter, but Valerie says, "Issues directly related to [his daughter] accounted for more than 90 percent of our marital strife." With her stepchildren not living with her and their father, he tended to bend the rules for the kids when they came over. But Valerie felt that her husband was teaching his daughter that it was okay to disrespect her.

And being so mired in the situation, she couldn’t see the situation from her stepdaughter’s point of view. "It’s common for kids to feel jealous in joint custody situations," says Bartell. "They feel like a visitor in their dad’s home." But stepmothers can also feel jealous of the attention and favoritism their husbands display toward their biological children.

Valerie couldn’t help but let her jealousy bubble to the surface after she and her husband ultimately decided that his daughter, now a teen, wouldn’t come to the house as long as she refused to follow the rules. Her husband didn’t stick to their agreement and started sneaking his daughter over when Valerie wasn’t home—and Valerie found out. "I felt betrayed, like he was sneaking his mistress in the back door," she says.

And during these trying times, Valerie considered divorce "more often that I’d care to admit," she says. But she stuck to her guns: "Initially, pride kept me from walking out of my marriage. I refused to let his daughter be the victor." But pride wasn’t enough—Valerie turned to friends for support. Only after she accepted the fact that her stepdaughter may never like or respect her did Valerie make the decision to continue to show her kindness and compassion. Ultimately, it took Valerie until her stepdaughter was nearly in her twenties for them to get past their issues.

Though Valerie didn’t seek professional help, Bartell recommends getting counseling if there’s a lot of fighting, you feel your marriage is in jeopardy, you’re under a lot of stress, or if you feel like you can’t resolve your issues alone. "The rate of second marriages breaking up is higher than first marriages," says Bartell. She says it’s also useful to seek advice even before you move in with stepchildren. "It’s powerful how many mistakes parents can make," she says.

For the best chance at success, Bartell says, "It’s important for the biological parent to do all the disciplining while the stepparent should just be a friend." That way, it’s less likely the kid will see the stepparent as the enemy. She recommends that the stepparent take this non-disciplinarian friend role for at least a year and then gradually phase into a parenting role. It’s also important for a stepparent to move into the relationship without the fantasy of ever being a full parent—and the biological parent has to think this way, too.

Stepparents often worry that they’ll never love their stepchildren as much as their biological children, and Bartell says that they shouldn’t expect to love a stepchild like their own. At the same time, however, the stepparent must do their very best to provide a home where the stepchild feels safe and gets ample attention. And if you are feeling that tug toward divorce, "Make sure your children aren’t sabotaging your marriage," says Bartell. "Go back to the beginning of the relationship and remember what brought your families together in the first place."