I often think of J as a character that has a lot in common with other manmade beings from literature such as Frankestein by Mary Shelley , Pinnochio by Carlo Collodi or The Golem by Gustav Meyrink.
Why may you ask? Because even if J didn't had much screen time in the MD show, the fandom gave her a lot of character development.
One certain fanfic that shaped my vision of J was "REQUIEM" by pocketknife(A03), also known on Tumblr as Nuzipilled. The way J is presented shows she's always tied of the past, more specifically for the human girl Tessa which in a way shows she opposes her own nature of a simple machine. This fact also leads V and N to try helping her get over it somehow. Now I do believe that in the fic both of them help her out of kindness but I have a different perception on how this kindness worked in J's case. Tessa's death was a strike for all three of them and once Cyn was defeated N and V should have felt completeley free from the past yet in Requiem, once they got to relax, regrets and remorse start filling them for Tessa's. Why? Because that girl was the only person who truly saved them and loved them as a family yet they couldn't protect her from Cyn. V and N knew J loved her the most and would think about her for the rest of her life. This is in a way a bone in the throat for V and N because it reminds them of the past. Something they are not fond of (scared) to think about now that they're truly free.
So they helped J to stop mourning Tessa only to feel themselves better. As if J's pain is the last reminder of their dark past.