To keep up with official news or find where to watch completed OVAs, you can check the following resources:
Since the original 4-episode run is completed, are you looking for for similar "elder sister" themed anime, or were you perhaps thinking of a different series entirely?
Aneki … My Sweet Elder Sister: The Animation (2007) - aniSearch.com
While there is significant interest in long-running series, is actually a completed 4-episode OVA (Original Video Animation). There is currently no episode 14 in production or scheduled for release, as the series concluded its run between 2007 and 2011.
Another story involves a student caught taking photos of his swimming teacher, leading to an unexpected proposal from a second teacher. Why the Confusion About "Episode 14"?
The search for an "episode 14" often comes from misunderstandings of different series titles or clickbait from unofficial streaming sites.