There are several reasons why they've (mostly she) picked Jeneora (it feels a bit crass to call it Jeneora's Rock, now, considering) and most of them aren't even sentimental.
The first, and most important, is that the infrastructure around the plant factory is intact, already set up to manage food and water production, and, theoretically built to handle more than the two plants its town originally held. Its factory is essentially a salvaged bit of one of the spaceships that fell, after all. Those weren't made with things like 'plant scarcity' in mind. Which means it can handle more than just two without any issue. The destruction of the town itself is a problem, but comparatively speaking, it is much, much easier to rebuild houses than to rebuild an entire factory for assisting plants in their matter creation.
The second reason, also pretty important; not only was Jeneora recently destroyed, but it was recently destroyed and then left with a water purifier in a somewhat ineffective attempt to make up the difference. A tiny portable water purifier like the one Yvette gave the residents is not the sort of thing that could actually keep a whole town going, but, well. It could certainly buy them time. It's likely that there are still people stuck there, surviving off of stores and whatever moisture they can hunt up from the local worm population or other available sources. Then along with that, yes, part of it was sentimentality. She knows some of the people still stuck there, and that matters to her more than it perhaps logically should. Cut her some slack, she’s only (mostly) human. She wants to fix what was broken in front of her, and if that drives them to work harder to save people, then all the better.
However, these are not the only considerations. More long term, it really doesn't do a damn thing if they feed people and then just give them nothing to do. Half of Jeneora's original problem was that it... kind of didn't have anything going for it, economically speaking. It was a place survivors huddled that had food and water, and while that was definitely not nothing, that was also clearly not enough. It would keep them alive, but it would keep them small and ever reliant on their lifegiving plants, exactly like they had been for the past hundred-odd years. Not a very good proof of concept to Nai about how humans can grow past being parasites that squeeze plants dry. Therefore: Jeneora needs to have some kind of industry.
That gets into the third reason why they're going with Jeneora; it has a large deposit of nearly chemically pure silicon a comparatively short distance away from the town. Zazi isn't always helpful, but when they are, they are extremely helpful. It turns out that asking the hivemind that is mostly based underground about stuff that is underground works pretty well. Silicates are abundant on this dustball of a planet, but pure silicon, which oxidizes when exposed to oxygen and becomes the silicates in question, is significantly more rare. Most often, acquiring it in its pure state means a lot of chemical processing, expensive infrastructure, and labor. Not having to go through all of that? Kind of a big deal, actually. Especially if they can, say, have the citizens of Jeneora do something more than simply selling their new prize off to the highest bidder.
Funny thing, but the primary component of modern solar cells? Pure silicon. Solar panels people can actually use to power things are much more immediately valuable to trade than 'this element that could in theory be turned into a thing.' Their creation is complicated, but the invention's already been done, and they don't need to necessarily make the most cutting edge solar cells the market can provide. They just need to make ones that people can use. From there, trade and economics can start to make up the difference of the things Jeneora doesn't have.
This is, of course, a massive undertaking that she is not at all qualified for. Fortunately, having access to Nai's large library of very bored, perfectly healthy plants that she knows exactly how to leverage is quite an equalizer. Nai will tolerate her plots of rapid industrialization if she has a plan to hand him that will clearly not kill or even hurt any plants. With so many of them, they don't have to stomach the exhausting change of what things they are making. They can just specialize. Which is to say: she can write up these plans in her goddamned sleep, and this is almost quite literally a plant engineer's dream job. Certainly hers. With Nai's assistance and psychic snuggles, she doesn't even have to sleep or eat.
To say she is having the time of her life would be like saying space is big. It is exactly what she has always wanted to do with her life, it is fulfilling and interesting and challenging and it matters. She's not stuck at a senior engineer's heel, handing over boring optimizations of requests the board of investors have made, keeping her head down and being a good and dutiful worker bee for a decade until she's given real power. She's not stuck on a sand steamer with an unreasonable stack of expectations, idiots for bosses, and the knowledge that she's assisting in the ongoing torture of something pure and beautiful. If she had dreamed of an ideal future for herself, she wouldn't have been able to come up with something so perfect. Yvette hasn't figured out how to use Nai's gate to literally float, but it's hard to tell from observation.
