Your family-made tree fort is very special, indeed. I admire how strongly it has been built, using a tree along with some posts and footings to keep you and your guests safe. I’m sure it will stand up to every kind of weather. You must have had so much fun building it.
Does your dog rush around your tree fort because it is scared of lightning? My dog is fine with lightning. Just don’t bring out a vacuum, or a rake, or a garden hose. Those terrify her.
I hope you get to share your tree fort soon with friends and your granddad who helped you build it. You have a very special place to share.