This is literally close as you can stay to the currently active fissure (fissure 8). If you want to experience the beating heart of the Lower Puna eruption, this is *the* place to stay. At the time of this writing, there is no legal area from which to view the lava directly, but there may be one soon.
Despite its proximity to the active fissure, it's totally safe. We came with our baby daughter. Air quality was good thanks to the trade winds, and most of the truly noxious stuff gets generated at the ocean entry point (and then blown off to the west along the coast). Furthermore, Jacklynn has a sulfur dioxide detector, which has shown safe levels the entire time, but the cottage also has an air purifier if you’re still worried.
Even if you can’t see the lava directly, being less than 3 miles from the fissure is incredible. The volcano is continuously generating its own clouds which reflect the bright light of the lava back down to the ground, causing a wide swath of the sky to be filled with an eerie red glow. After baby bedtime, my wife and I sat out on the patio and just stared at the shifting crimson clouds for almost an hour. The coqui frogs make it pretty hard to hear the eruption itself, though occasionally we caught little sounds that may have been lava sloshing in the distance.
On the retreat property, there are also (as of this writing) a number of steam vents where hot steam is constantly billowing out of cracks in the ground. These are all downwind of the cottages, so their slightly sulfurous odor won’t affect you unless you go exploring.
Another cool thing: At least when we were there, the entire area from Pahoa down to the retreat had a unique smell that is hard to describe. It’s more sweet than sulfurous, and I miss it now that we’ve left.
An alternate place to stay would be somewhere in Nanawele estates. You’ll probably get a broader swath of red sky from Nanawele. However, I still think Jacklynn’s place is better: the view from the cottage balcony is amazing, and Jacklynn is a great resource for tips on exploring the area if she’s around.