My relationship with my grown children has changed a great deal. (they are 29 and 28)---
Of course I am still their mother, that doesn't change. They are more likely to give me advice these days than I am likely to give them. I just try to take a breath when the old mommy think pops in my emotional self and take a look at them as they are now.
Now and then though, they still want "mom" to be "mom"...
I guess it is safe to say that your parents never stop being your parents, but as you get older, you can change your behavior, which tends to modify theirs.