The dilemma My husband and I have been together for 10 years. During this time I have watched my stepdaughter who lives with us part-time (we have no children of our own – my choice) turn into a self-obsessed, lazy adolescent who is too busy taking selfies to help with chores, like setting the dinner table. I feel like a slave cooking and clearing up after her while she flicks her hair and pouts into a screen. I am getting bitter and resentful. Of course I want us to be a happy family, but I feel so out of control. The one time I did rebuke her, I ended up being told off by my husband that it was not my place to do so. I now avoid being around her when she stays over. I’m afraid I’m beginning to dislike her.

Mariella replies Perfectly possible. The presumption that because you love a partner you’ll unreservedly love their offspring has always seemed a mite unrealistic to me. It’s certainly easier when the child in question is young, unformed and less complicated in their needs and opinions. Once they start morphing into adults and causing havoc with those tasked with raising them, they do briefly become creatures that only a parent can love. You mustn’t take it personally.

Turning into a “self-obsessed, lazy adolescent” is evolution and your stepdaughter’s selfie habit only confirms her as part of the flock. Becoming impossible to live with is what teenagers are meant to do. How else do we let them go out into the big wide world and away from us in just a few short years’ time? Watching Harry Enfield’s Kevin character is helpful to restore your sense of humour and confirm the lack of originality in a teenager’s bad behaviour. Our family favourite is the sketch where he metamorphoses from happy-go-lucky child into depressive, myopic, malcontent at the stroke of midnight on his 13th birthday.

Hormonal surges and uncontrollable emotional peaks and troughs cause mayhem for those committed to parenting and for those on the inherited peripheries where maintaining cordial relations must feel like an insurmountable expectation. You’re lucky you’re only having to cope a couple of nights of the week – imagine what her poor mother is going through.

Becoming impossible to live with is what teenagers are meant to do

That said, if you’re less vulnerable to the shifting tectonics that are causing rifts, you’re well placed to provide the voice of reason and score approval from all concerned. In the hormonal storm, an emotionally detached adult can be a safe haven and there lies an opportunity for you to help steer your stepdaughter through these troubling times. Part-time, how much housework can she create? How about, instead of confronting her about her lazy lifestyle choices you use your time together to befriend her? Let your husband do the dishes and you two settle down to some tacky TV, or scroll through Instagram together. You can afford to be lenient, creating a friendship you two can enjoy for decades, rather than just a pyrrhic victory when her Dad gets her to clear the table.

It’s tough being a stepparent, but there’s a big difference between struggling to find easy affection and failing to summon up empathy and kindness. A baseline expectation has to be to behave like a compassionate adult, accepting that your relationship choices have led to you inheriting a degree of responsibility for a life whose existence in yours wasn’t directly chosen. The residue of guilt that seems to be a staple of separation will also be exacerbating the situation. Parents often try assuaging their own feelings of culpability for a relationship breakdown by allowing a damaging degree of leniency. Just because there’s a vacancy doesn’t mean you should take over as bad cop.

You say you two don’t have children because you didn’t want them. It’s interesting that you should feel so comfortable with that unilateral choice if, as seems the case reading between the lines, your husband might have made a different decision. It’s admirable that you know your own mind so well, but I do get a sense that you are used to running things your way and there’s nothing like a teenager to make a house feel overcrowded. So is your frustration born of something other than this child’s laziness? You say you feel “out of control” and there’s quite a build-up of tension and frustration in your letter. More often than not that springs from somewhere other than the target of your ire.

Your stepdaughter may well be metamorphosing into an unbearable, lazy, superficial adult, or she could simply be behaving like the rest of her contemporaries. Either way disliking her won’t help, but improving your relationship with her certainly might. Meanwhile, for help with the housework maybe it’s time to tackle your husband…

If you have a dilemma, send a brief email to mariella.frostrup@observer.co.uk. Follow her on Twitter @mariellaf1