Long story short, I have 3 SD's - 12, 15, and 22. The younger two have a different BM than the oldest and she passed away from cancer 2 and 1/2 months ago. The younger 2 have also lived with DH since the divorce from their BM and since she's died, obviously, they're with us 24/7. My relationship with all 3 is very, very good and I love them all more than I have words to express. I'm not a BM and DH and I have been married for just over a year.
My 22 y/o SD has lived on her own since I've been with DH and has a 2 year old son whose BF is not in the picture. DH and I gladly help her all we can financially as well as babysitting, etc. According to my SD, she and her BM have a lot of problems. I've never even met her BM, so I don't really know the depth of the issues, only what SD tells me. I make it a point to never bash her BM in any way, but just to be there when she needs a shoulder.
Since my oldest SD has never lived with us, I've always approached our relationship as a friendship. In fact, I'd call her one of my best friends. Today we were talking and she out of the blue she told me that I'm the closest to a "real mom" (her words) she's ever had and she loved having a "maternal figure" (again, her words) in her life. It kind of stunned me because I never considered myself "maternal" towards her - at least not in the same way that I do towards the younger SD's.
I'm just looking for some feedback on how others approach their relationships with adult SK's.