Phil didn't talk about Leanna, but he had her film his DSP Tries It videos. She was in his cooking videos. She was in the condo tour videos. She was a moderator in his chat. She played co-op games with him. She would pop into his office regularly while Phil was working. She was in his travel vlogs. She was in his pet videos. She was in the Christmas tree decorating videos. She joined him for Q&A videos. Phil shilled her soap company on every prestream slideshow. Phil mentioned her job, her family, and her medical issues. Phil let us know when he had to end the stream early in order to wake up sick Leanna so she could make dinner.
Yeah, we barely knew Leanna existed...
She was more of a fixture in the YouTube days, when Phil was more, for lack of a better term "active" with his content. I don't remember her appearing much in the Twitch days, when Phil went full hermit/became even lazier and refused to film content outside of his "office." She'd still get some mentions, sure, with the medical issue definitely being one of the bigger incidents, but that wasn't exactly a common occurrence.
I think if Phil knew anything about Khet's personal details, it would probably come out on stream. As it is, we do get a few leaks every so often, it's just that Khet is an incredibly boring person and those mentions are forgettable and basically amount to "Khet is working" or "Khet was playing Skyrim." The social media mentions are equally boring, usually just a picture of some microwaved meal Phil insists is homecooked. There's also exciting stories like Khet goes to the gym, leading up to the epic of Khet wanted an exercise bike, but there were delivery/assembly shenanigans.
If Phil ever got desperate enough to start doing vlog style videos again, I could see Khet making a few more appearances, but I think Phil is too paranoid/lazy for that, especially when he'd make more money just from putting on a vest then he would uploading something to YouTube. And I certainly wouldn't disagree that Phil and Leanna were significantly closer than Phil and Khet, but I still don't think she was that prominent in Phil's life, she just stands out more than Khet because Khet is so boring that most of the "arcs" surrounding her are actually more about crazy family members. If she ever manages to do something vaguely interesting, I imagine we'll hear about it almost immediately on stream, just like we got those sick details about Khet observing that people might have been acting foolishly when they were buying toiletpaper, or that her ex made her watch Marvel movies and now she doesn't like them.