I know how it feels to be one of several sets of grandparents, and as second and third marriages are quite common these days it's an increasingly frequent phenomenon. In my case, one day I was a single, full-time career woman and the next I found I had inherited two baby stepsons.
Later, with my present marriage, I've found myself the stepmother of two very grown-up, modern stepdaughters. In this kind of ever-increasing extended family, if both sets of parents of a couple are alive there will be two sets of grandparents. If a couple turns to one set rather than another, sees or visits them more frequently or are in closer proximity to one set than the other, it's easy to understand how jealousies and rivalries come about.
It could be that one set is better off than the other and can afford more financial support in the form of helping with a house purchase, holidays, school fees or a new car. If so, grandparents can feel like the poor relatives if they want to see themselves in that light. Another way of looking at it, however, is to be happy that your children have generous benefactors who can give them a standard of living they and your grandchildren wouldn't otherwise enjoy. You, in your turn, can give your grandchildren gifts which mean just as much, if not more: time, interest, outings that cost little but are enormous fun, love, focused attention, simple games that you regularly participate in.
More than one in five people in the UK (22%) are grandparents and nearly two-thirds of people over 50 are grandparents, so a greater part of a person's life is now spent as a grandparent than any other stage of their life.
Taking on a grandparenting role will be different with each of your children - and stepchildren - and you'll have to be something of a chameleon to tune in to each family set-up. I think I learnt hard lessons when I became the stepmother of two little boys. It was very hard and I often felt emotionally bruised until I lowered my sights and decided a better approach was simply to try to be their friend. I think this scenario is played out with step-grandchildren where there isn't a blood tie, only a love tie which can be just as strong, but where you feel you have fewer rights and have to tread carefully.
Your step-grandchildren don't know this - you're their granny and that's what you can be - their most loving friend, possibly even more loving than their "real" gran or grannies.
These days you may be one of many grandparents. In one stepdaughter's family I'm one of four grannies and two of them are much higher ranking than I am in terms of blood ties. I try to know my place in the hierarchy. But whatever the grown-ups think, the grandchildren will arrive at their own decisions: you could be a lowly granny - number three or four to the adults - but number one to them.
My eldest grandchild, the six-year-old of one of my stepsons, gave me a note recently that brought tears to my eyes. It said, "My best granny is Granny Miri." And if you're lucky you may be invited to be a supernumerary granny. After a communal outing, the small son of one of my daughter-in-law's girlfriends asked if I could be his granny too.
It would be a pity to allow rivalries between grandparents to come between you and your children and grandchildren. In any event, your children won't have the same point of view and will wonder what you find so upsetting, or simply lose patience with you.