Yesterday Cari commented on the process that slowly evolved after her grandduaghter was born - and that's an important point. As you very well may know, if you jump in too quickly without assessing a situation, you're more likely to get into trouble.
As a club sandwich boomer with a first grandchild, try not to offer advice unless asked. You don’t have to say whatever comes to mind. If your suggestions are requested, present them in an open-ended way so that your adult children are free to accept or reject. Remember how you felt when your mother or mother-in-law shared their opinions about how to raise your children?
Talk about the challenges. Don’t be afraid to communicate with your children in a non-confrontational way. You will all be more comfortable and appreciative of your relationship if you don't let issues fester. However, don’t expect that the results of your talk will follow a pre-determined path. Often the fact that there is conversation is more important than the outcome of any one particular discussion.
Be aware of your feelings. You may be ambivalent about babysitting often when it begins to impact the pursuit of your personal interests. Choose a balance between your own needs and the responsibilities of your grand-parenting role. It's necessary to set the kind of limits that work for you.