I do for sure! We have our busy days where we go to the park and do crafts and lots of activities but some days you just have to sit back and just let them play. You can stick a fancy term on it like facilitation, but basically a big part of our job is to let kids be kids. Some days I have a bunch of stuff planned but then the kids are just playing so well together or have made an elaborate block city that I just don't want to interrupt it to move on to some planned activity. Don't feel guilty at all, free play is just as valid and important as any other activity you do with them.