Dr. Laura,
I do not personally belong to a blended family, but have known and worked with many people who are. The thing I find most disturbing is the immediate desire to disown stepchildren. The best example I can provide is one I had with a co-worker.
I was preparing to send a fax in another person's office and was feeling the need to engage in a little small talk with them. I immediately noticed she had pictures of kids on her desk and asked if they were hers. (I never assume pictures of kids on a desk belong to that person as some people take insult when it's their nieces or nephews - especially when they are not married.) Her response was to say proudly that yes, the picture of the little girl was her 6 year old. Clearly as an afterthought, she mentioned the other 2 kids, who were clearly in high school, were her husband's.
Since that time I have had at least 2 identical conversations with co-workers in blended families. They proudly claim THEIR kids and then sort of give an obligatory explanation of the shame that was the unfortunate result of their spouse's previous marriage or poorly chosen relationship.
That is the problem: stepparents not wanting to truly take on these kids as their own. If this is how they address the kids to people at work, how can they possibly be models of love for these kids at home or with other family members? Why do these people refuse to say something like, we have four kids, without separating out who belongs to who? I can somewhat understand the ladies wanting to note that perhaps older children are not theirs in an attempt to show that they were not teenage mothers or that they are not older than they actually are. I could also understand revealing this information in an attempt to get help in strengthening a relationship - such as when people call your show. But in every case the result is the same, stranger or confidant, these are my kids, and those are well, his or hers. I just can't help but think if this is how you introduce your family, is it really a family at all? A family is joined by the bonds of marriage, naturally or blended, and if stepparents treat their spouse's kids like foreign exchange students who happen to be visiting until they graduate, then the family and the marriage is a sham.
Best,
Sarah