I understand how you feel. I have one very independent daughter who married a boy who has two younger brothers and no sisters. His mother idolizes her three grown up sons and they, in turn, adore their mother because she is a very generous hearted person who has always put her sons needs above her own. She lives for her sons and their families and is the most giving grandmother to her seven grandchildren.
When our daughter was expecting her first child I found this situation so challenging to live with, and when first grandchild was born I definitely sensed that my daughter was keeping me at "arm's length" and trying to balance/manage equal time to both grandparents! I really struggled with this because in my mind I expected my daughter would want more of my support and experience, simply because I was her mother! Several times during those early years I sat and explained to her how I felt, that she was my daughter and as much as I liked her mil, I still felt a bit resentful that she kept herself somewhat "distant" from my overwhelming desire to have a close adult mother/daughter relationship, and that I was very conscious that she was carefully sharing her life and grandson equally between the two of us.
Looking back now, what a waste of emotion that all was! I should have realized that we had raised an independent daughter and she was choosing to lead her life her way and that was how it was going to continue! But the irony of this story is that fast forward 15 years, they now have three children, we live in the same town and can enjoy being in our grandkids lives. But we also involve ourselves in our "retirement" hobbies and see our friends frequently.....we love our active lives! Whereas our daughter's mil is still "laying down her life" for her sons and their family and she is beginning to become a concern. She is now a widow - only takes holiday with her sons and their families, had no interests outside the home and very very few close friendships because her sons, their wives and her seven grandkids are the centre of her world and her one and only interest in life. Our daughter still has an independent streak in her, but generally speaking we get along well. I now understand the role I play in her life - and I realise she is respectful and grateful that we have both developed interests and friends beyond the limits of our immediate family. We still have the energy and desire to embrace life and yet take pleasure in being active happy grandparents to her three great kids without wanting them around 24/7. It's all work out very well.......funny how life comes full circle at times!