So in my WIP I have a limited third person POV. Most of the time I am in Valorie's head but for one chapter I switch to her sisters POV. Her sister always calls her Val. With the only exception being if they were like in court and a judge asked her Valorie's full name. lol. So since she always calls her Val. Should the narrative then call her Val when I am in her head with the third person POV?
I'm assuming when you say 3rd limited you also mean that for the chapter in her sister's POV. If that's the case, then it makes perfect sense for the narrative to use Val, since it should read in the sister's POV. I'd argue that it shouldn't be any other way. In 3rd limited, the narrative should reflect all the POV character's biases and quirks. That way the reader gets a colored interpretation of the world through the lens of that character. 3rd omniscient provides more wiggle room on matters like these.