First of all, congratulations on becoming a grandma. 
My advice is to try to go with the flow.
Whatever the circumstances, new parents are just that - the parents - and they are ones to shoulder the responsibility and take the decisions. As a grandparent, be guided by those decisions and try to be supportive of them.
As a mother to two married sons, and no daughters, I can assure you that your role can be just as important as that of the maternal grandma, but it's not a competition. It's not a race, either - you might not be the one who has most involvement to begin with, but these things evolve over time.
I can understand (and am sorry ) that you are worried that your little dgd is poorly, but again, there really is nothing you can do, unless asked, except be supportive.
I really hope that all goes well for both the new family and your part in it 