I'm a grandmother - both my children have two children.
I can only speak for myself - I was/am intensely in love with my children, it's like a hand that grips my heart whenever I see them. This has never changed since the first days that they were born.
When they had their own children it was pretty much the same feeling - a rush of love that has never abated. Their presence in my life is such a wonderful gift !
I'm fortunate that they live quite close, so I see the children often. I marvel at their developing characters - it's like getting the whole motherhood experience all over again. A chance to do things better this time around.
I agree that it's difficult to see your AC going on the journey of being a parent ! My son is a single father so he has had to deal with a horrendous relationship breakup as well as being mother and father to his two children. It was heartbreaking to have to watch that happen. I'm now the co-parent to his children so I see them every day and deal with all the practical stuff as well as enjoying being granny. My daughter is a workaholic and never seems to have much quality time with hers , so yes I worry about that too - worry that one day she'll wake up and realise that she has missed so much of their lives . But. I can't fix any of these things, just "be there" and show my love in practical ways like doing my daughter's ironing and picking the kids up once a week after school to hang out at the park.
I guess that I show love in practical ways, and always have. As my Dad used to say, love is something you do, not something you say.
I'd highly recommend grandmotherhood - I just hope I can continue to do it forever. Enjoy your little boy !