Here are some of my thoughts:
Considering that our culture has so many stepparents, there is not an accepted or prefabricated mold for their role. Our families are *supposed* to be comprised of Mom, Dad, kids (all living in the confines of their specific role). For those of us whose families don't fit into that mold (stepparents, kinship care parents, foster parents, single parents, gay parents, multi generational families living outside of a larger, supportive/similar culture, intentional living houses/co-parenting with non related individuals, etc), we must come up with our roles mostly from scratch and with borrowing from other molds. In some ways, it's very liberating. The existing mold of Mom, Dad, kids and what their roles *should* be, is (IMhumbleO) suffocating and restrictive. *I* don't think any mold is very healthy if we are feel like we *have* to conform to it. Better that we create unique structures that are healthy for us, as unique families, and that nurture our children more completely.
Stepparents challenge the our set of roles. (When we forget that we are NOT our roles, we become very upset.) How often do we read a post on Mamapedia from a stepparent who feels like he/she doesn't fit in or "get respect". Or from a mom/dad who feels displaced by the new parent or relationship.
In reality, more people to love our children is great! But, when our authority, or our place in our familial structure is threatened, we get...grouchy.
I'll be honest, if another woman came into my children's life as a stepparent to our children, I might feel scared of being replaced, or angry if she didn't go along with what *I* already have set up. My role, most certainly, would shift. Change doesn't always feel comfortable. In truth, I cannot be replaced. I am unique and the skills and love I give my children is unique. I'd have to make it work. Let's hope I don't have to ;)
When my stepmother came into our lives I was, at first, thrilled. I was glad my dad had found someone to share his daily life with. I invited her into my life and heart. I was 13. Unfortunately, things didn't go smoothly from there. I was, as an adolescent, upset that their marriage had shifted our family's roles and I felt like there wasn't a place for me anymore. It's a long story, but essentially, after breaking my trust she refused to give my dad and I any space to ourselves. I wanted to be able to eat lunch with him once a month by ourselves, or take a fishing trip once a year...something like that. She felt threatened and asked him to choose between us and our needs. Oh dear, what a messy time. It took a decade to sort out.
Some of the best parenting advice I received was 1.) be the person you want your child to see 2.) everything that comes you will be able to handle - that was in relation to labor, but I've found it helpful in a myriad of situations.
What I suggest to new parents is a parenting formula based on: Flexibility, Consistency (the two are a good team, and do not oppose each other), and Love, Love, Love.
What I would suggest to a parent who is going to raise a child who is not their biological child, is based on the same principles. But I think needs an extra dose of patience and empathy. Flexibility is paramount. And team work (which is tricky because instead of including one other parent, now includes X amount of adults). *Communication*. Being able to understand that rejection, coming from children, isn't the same as from an adult. Often, if kids are given the space to have big feelings (confusion, anger, frustration, grief, happiness, joy, calm, etc) they will feel safe and stop rejecting. If we try to "strangle" their feelings or punish them for the feelings themselves (not to be confused with their actions based on feelings), the feelings will build and they will push us away. Now, that is not to say that we should be fine with being treated badly by *anyone* including our kids. But, we can let them have their feelings and deal with their feelings in healthy ways at the same time as asserting and communicating our needs and boundaries.
I'll tell you, every difficult-difficult moment with my little niece is worth those moments of loving bliss. We have had to create new roles in our family, but as the result she is *mostly* doing very well. I can see my love having an affect on her body/mind and it is darn rewarding. It's taken MONTHS to get to a place that feels pretty stable, most of the time. It's been hard work, beautifully challenging. And it is worth it.
Also, I think sometimes we confuse uncomfortable with bad. Finding our place in a preexisting structure - while it is shifting to make room for us (be it a work place, home, family, town) does not always *feel* awesome. So we need to be ready for that process (not that it will always or mostly be uncomfortable). When kids are involved, that becomes more complicated because their developmental process/ability is shifting all the time. Our roles, in relation to them, must shift with them. Ugh. It takes time and energy, doesn't it.
I think a valuable tool, if AT ALL possible, comes from both sets of parents being able to communicate. I can't speak from personal experience but... One of my best friends is doing a fantastic job of this. She and her ex have three children (one with a different bio dad), he just had a new baby with his partner and she (his new partner) had a child already as well. My friend is also partnered with a man who has a child. So, between these four parents - and their X amount of exes - they have six children. Holey Cow, what a wild ride. At first, my friend and her ex had a really rough relationship. Terrible, draining, angry court battles and the such. But somehow (well, not somehow...they've put an incredible amount of time and work into their relationship) they are at a point where everyone is talking to everyone. They up date each other, do birthdays and big holidays together and try to make life easier (instead of harder) on each other. The result shows in the kids, who are doing far better than they were before the team work began. They are happy, healthy and balanced. They don't get to pit parents against each other and feel safe and supported in all homes. They don't resent their parents or their parents SOs. It's not all rainbows, but it works and everyone is doing better. My friends ex's new partner (what a mouthful!) and my friend have gone out to coffee. My friend's new partner's ex and her have also gotten together on a couple of occasions. They check in. They are all one big team effort. Just because our relationship, as lovers/life partners didn't work out, doesn't mean we can't still co-parent effectively.
Redefining their roles has not been easy and has been scary at times. But their kids have benefited from their process. In huge ways.