I love kids, we all love kids, I have a good handful of my own kids and loads of nieces and nephews, they are all always welcome to my home, this is why I first kid proof everything beforehand. Some things are common sense, a white sofa and red fruit juice, a rambunctious 3 year old and a trampoline without a net, but there are some other things you want to check out with your outdoor living space before just opening it up. First you want to check safety before anything else, if you have pools always keep the latter up or keep it locked with a gate. If you have a large yard but you are on a main road make sure you have a fully locked gate to keep young children for making a run for the ball they just tossed down the street. Keep all grills on a steady patio and not on a slanted grassy area; don't keep your fire pit by the sand box or swing set. If you have a swing set be sure to check it regularly, wear and tear can happen anywhere, you don't want the kids to fall off a swing that you didn't realize was broke or the side of a slide that is starting to tilt. And if you have a large sandbox, always keep a top on it, this is the perfect for neighborhood cats or pests to use as their outdoor litter box, you wouldn't let the kids play with an indoor litter box I am sure you wouldn't want them playing with an outdoor one.
Now that you have made sure they are safe, you can be selfish and make sure your loved outdoor wooden furniture and accessories are too. First things first, NO crayons!!! My kids love crayons, they love to color and paint and use outdoor chalk, and they have a space just for them to do that, but every now and then, not sure if they forget where they are, I didn't get them paper fast enough, but I will find crayon marks on my furniture and I do NOT like it!! They have their space and you have yours, it's ok, adults need to have a space inside and outside the house that is a place we can enjoy, I'm sure the kids wouldn't like it if we told them they can't play in the sand box cause it makes a mess of the grass…
Their spot is for play, and yours is for relaxing, you work hard, you deserve it. But in the chance they did get juice spilt on the pillows or crayons on the wood try these tricks to get them out. If you have a crayon mark on your wooden chair try removing it with Murphy's Oil Soap, if this is a no go there are other options, just try them on a part of the chair you don't see first, just in case it stains as well or lightens the wood.
Try WD-40 or even Avon Skin-So-Soft, that stuff is used by moms for so many crazy things, but it's tried and true and really works. Another miracle washer I use often is Dawn dish detergent, since Dawn is a grease cutter and most crayons are oil or waxed based using a little with a good sponge should help get most stains out. Dawn is also great for all pillows, blankets and even stained clothing, so even if your pillows cannot go in the washer add a dab of Dawn and a good scrub and you should get most the stain out, just don't wait.
Unfortunately there is not much you can do before hand to the furniture, unless you don't allow the kids near it and well, let's face it, that's kind of not fair. So once the stains are out just remind them, food and drinks at the outdoor eating table, not the lounge set and crayons are for indoors. As for chalk, chalk is for the sidewalk, hard to believe but chalk can be, if left on without knowledge of it, too long very difficult to get off wooden furniture, trust me!