My parents are like that, and I'm grateful! They help schlep the kids from field to field, go to all recitals, plays, etc. They also help me get the kids to their activities - I couldn't do it without them! Just wait - the bond my children have with them is unbelievable!

I'm not an only, but my sister lives far from here, so they focus on my kids. They know all of my friends, and talk with them at games (and talk to my friends' parents, who attend also). Sure, they walk in and out of my house whenever they want (and bring food - we have all of their holiday leftovers still!), but they won't be around forever, and again, they are like second parents to my kids.
Edited to add that minutes after I posted this, my mom showed up, asking if anyone needed a ride anywhere. I was just about to pick dd13 up at her friend's house, so mom saved me a trip! She also brought some pita chips. Today, I got stuck at the store longer than I thought, no problem - called my dad. Over the break, not only did my mom bring the little ones to BAB at the mall, she also took my kids to the movies by herself, and brought dd13 and 5 of her friends to the mall.