Get used to hiking if you want to get away from the rowdies without a multi-hour drive!
Deeks Lake is beginner-friendly, steep in parts, a fairly good trail, well marked, long and hard enough to know you worked to get there but not crazy. Lake is excellent, pretty, remarkably low in bugs and high in hungry small fish. (Low bugs, not no bugs! This is bug country after all.) Fish are small, numerous, easy to catch and frankly not really great eating fish, skinny and pale but that doesn't matter much for your purposes. Bring worms, a bobber and a way to get it floating twenty feet out, all you need for kid entertainment and dinner. Much excitement and joy will result when the bobber bobs! Camping to left when you reach the lake, more on gravel flats where the creek enters the lake, follow the trail to the right around the lake. If you have two nights a day hike to Deeks and/or Windsor, or along the HSCT as far as you like are nice.
Cheakamus is very suitable as well. Easier trail. Beautiful. Less backcountry feel. Worse bugs.
Don't count on fish though, they are much bigger, better and tastier but not nearly as easy to catch. Do the worm thing at Deeks and you can pretty much count on dinner.