Most parents find raising their own biological children somewhat of a bumpy experience. However, in theory, at least, their authority is unquestioned, and they do have some control over the influences to which their offspring are subject.
But in a blended family - formed by a remarriage that includes children from previous relationships - the web of influential relationships often becomes wider and less clear.
Dr Jadis Blurton, clinical director of Therapy Associates (HK), has experience with the joys and difficulties arising from such a domestic arrangement - not only from working with such families, but also in her own home life.
'I have six children from a blended family: one adopted child from my first marriage, two biological kids from my first marriage, two stepchildren from my husband's first marriage and one child from our marriage,' says Blurton. 'So, it's a yours, mine and ours situation.
'The complexities are so huge you cannot know what to expect from one moment to the next. There are lots of things you can't control in terms of other influences on your kids' lives, and not just from your ex-spouse and your ex-spouse's new boyfriend or girlfriend.'
However, the way her blended family has developed shows what is possible if, as she puts it, you 'maintain a lot of flexibility and a good sense of humour'.
How well things have worked out is perhaps best illustrated by some of the roles taken by members of the various families at her stepdaughter's wedding. At the ceremony, the bride was escorted up the aisle by her own father (Blurton's second husband) and Blurton's father (the bride's stepgrandfather). The maid of honour was her daughter from her first marriage, her son from her second marriage did the reading, and her son from her first marriage provided musical accompaniment.
'They've all grown up together, and they've become best friends,' Blurton says. 'So it was a very successful experience, but not without its bumps and difficulties.'
On the other hand, private tutor Peter Sun, 50, has experienced mainly the bumps and difficulties. When he married for the first time last year, his wife and her two daughters from her previous marriage moved into his flat, and it didn't take long for his initial joy to give way to tension and pressure.
While he was dating their mother, the girls, both in their late teens, called him Uncle Peter; now they are all living under the same roof, they are no longer so polite.
'My wife asked them to change their way of calling me, but they did not listen. I should be given some respect; they are living in my flat,' he says.
'My daughters are always out and not children who need to be pampered by their parents any more. It seems too late for me to develop a relationship with them.'
Wary of exerting his authority, he has refrained from challenging his stepchildren when they, for example, neglect to clean the bathtub after use or turn up the television volume early in the morning. Despite his prompting, their mother hasn't acted, either. 'She is caught between me and them. She said: 'If you accept me, you have to accept them, too'.'
When it comes to the behaviour of the children in a blended family, Ceilidh Halloran, a registered psychologist who has practised in Hong Kong for 10 years, urges the parents to take a developmental perspective.
'Creating a blended family with a two-year-old is different to creating one with a 15-year-old. This may sound obvious, but I think it is useful to think about what sort of engagement you expect. Your 15-year-old may not be off you or off your partner, but may actually just be involved in being a 15-year-old.'
Halloran believes couples contemplating forming a blended family need to recognise that love is not enough. 'We've come from our own families, and we have ideas around how we want our children to grow up,' she says. To reconcile these different views, 'it is important that people agree on a way forward, acknowledge there are likely to be some bumps in the road and formulate some kind of strategy for dealing with these. It is really important that the parents are united. They are the ones who are going to drive this train.'
Blurton says the parents in a blended household need to 'envision the way they'd like the family to be and then make their rules accordingly and apply them in a consistent way with their children'.
If the parents fail to recognise how things have changed, serious problems can arise, she adds. 'You have biological parents who won't allow their new spouse to make rules or have authority with their children because they're convinced that these new people don't know their children very well or may not know why their children behave in a certain way. If they do not allow the new spouse to have authority or a role with their kids, that's a real danger point.'
When it comes to relationships with previous partners, Blurton believes that while the parents in a blended family don't have to agree with their former spouses about the rules their shared biological children should follow, they should support each other. Different rules may apply in the different households where the child stays, but, in the same way different rules apply at home and at school, this doesn't have to be a source of conflict.
Although Halloran says not everyone needs therapy, nor is therapy the best approach for every problem, 'if there is any heat or animus around, then it can be really useful to talk as adults with a third person', she says.
And the roots of some problems can run deep. 'The new spouse may feel jealous of the biological children because somehow the biological children remind them of the old spouse,' says Blurton. Other destructive emotions can come into play if the creation of the blended family has been preceded by, or is taking place alongside, an acrimonious divorce.
'Parents need to stop and ask themselves how much of what they're reflecting back to the kids is due to their own feelings being hurt or their own sense of displacement or their resentfulness or anger at the other spouse,' she says.
Sometimes Blurton says she has to remind parents that 'these are kids, and they are not responsible for the situation their parents created'.
Even if negative emotion responses aren't an issue, then sheer lack of experience can create its own challenges. 'As they deal with babies and then toddlers, parents learn parenting skills,' Blurton says. 'It can be really difficult if your new spouse has never had kids.'
But as a location to raise a blended family, Hong Kong has a lot of advantages. 'It's a very compact city, there is help available and it is safe,' Halloran says. 'It makes a big difference if you're not travelling halfway across London for three hours for an access visit.'