I'd love to say she has no effect whatsoever, but that's really living with blinders on. I get along with both my BM and, to a lesser extent, SM. Both of them have a huge impact on my children, even to this day.
SM influences BD to spend time with her, and kids are upset that he doesn't spend more time trying to see them (DD has a pretty good leverage point, though, as she's going to be trying for first grandbaby here in the next year or so, which BD will only see if he gets off his lazy butt and goes out to see). While they were growing up, she exerted a lot of influence over how BD related to and disciplined DS, especially with regards to his ADHD. She may or may not have had a point - I don't know, because as I told my ex, even if it made the most sense in the world, I'm going to ignore her simply because she doesn't love my children and isn't doing anything out of love but rather out of "how it should be done," and she doesn't even have children. But my kids felt it, and it affected their relationship with their father.
BM is pretty great, but she still does things that either upset DH or that we question with regards to kids. It impacts how we do things with kids, if we can go forward with a schedule regardless of what changes she wants to make (at the last minute), etc. She impacts my life because she's in it and I'm in hers. I've also been known to run interference for her when she and I both agree DH has gone off the rails. Good thing we mostly get along.
