Yerin the genuine indeed.
As someone who kept up with her, she did seem to practice singing all day everyday and started learning guitar as well. She wanted to have a waaaaay more active career than JYP was giving her. She also didn't let professional inactivity prevent her from artistic activity, so, as she mentioned, she would write her own songs. And yes, she would hang out with fans and go places share her work like a small time musician would, and formed some buddy-like connections with some fans as small time musicians do.
Unfortunately, that way of life has dissonance with the big time idol market and all the insane possessive and entitled attitudes people get. Hopefully if things don't improve on the JYP contract, she'll eventually be able to get out and go indie. I think she would thrive as a Park Ji Yoon or Neon Bunny kind of artist.
Edit: Just have to add... You all know I love JYP, but in kpop it may be that no ball has ever been dropped as hard as Baek Yerin. She was a prodigy and they got her at age 11. She needed to learn properly still, yes, but she was already ahead of her own debut at 15. Just one year later she was doing covers better than the original artists. Now it was been 4 years since then with minimal opportunity. She is 20 years old, not some child. Her passion has been unrelenting. It is a crime against art to keep a truly gifted and passionate artist caged up in their young adulthood. People say IU got a raw deal but her young adult years have been far more richly rewarding in both professional activity and artistic networking with people all across the industry.