I think it's a legitimate opinion to think that five months is too long between updates (as a general rule), but I'm not sure if releasing shorter updates would be a well-working solution. As the different storylines get more and more tangled together, it might be harder to write updates which span only a few days instead of longer updates covering a set of events and scenes which Eva considers to belong together. Each chapter also needs a logical end-point.
I also agree that she ideally should perhaps plan ahead more than what it seems like she's doing at the moment. But to be fair we don't know the details about how she's constructing the story. She's given a few comments which give the impression that she's doing very little planning, but there's also a lot of things in the game that I assume have been planned long in advance. She mentioned in one status report recently that the new update contains some (for her) long-awaited scenes (Lena with Axel and Seymour?), so I think it's fair to assume she's got a lot of the story planned out, just not everything or the exact chronology of it.
She could obviously try to get ahead of the writing difficulties by always having a couple of chapters planned out in detail, as has been mentioned here a few times. But another way to do it is to instead plan a set of key events for each path at different points of the story, giving a general direction, and then more or less improvise from that—which I suspect is closer to what she's doing. Let's take Ian and Cindy as an example: I assume Eva had a specific or more general plan about how they would get together a couple of months into the story. With that in mind, she knows that the story needs several scenes that gradually change their relationship and impression of each other to the point where they end up having sex in a back alley after a party. Often it's easier to write scene B, C and D if you already know how scene A and E will play out, than to write scene C, D and E if you only have scene A and B planned.
It's obviously possible to both plan scene A to E and how they fit in with the rest of the story, but you can also just take the opportunities which arise as you write your way through the story. Some writers are more intuitive than others, and Eva seems to be one of them. In my opinion one of her biggest strengths is how she sets up scenes like those between Ian and Cindy, which gradually and very subtly change the characters's progression and their impression of each other. If she instead plans out all the scenes in advance, there's a chance they would feel less organic and more constructed. There's obviously a balance to it, but I don't necessarily think she's that far away from the ideal working method for her and the game.
