Update 8/12/14: New title suggestion - Supernatural: The Linda Tran Chronicles. Meant to remind people of another show about a single mom who is put in danger because her son turns out to be someone very important to the world, and rises up to the challenge like the badass she is.
And speaking of reruns, based on tonight's they could also take a page from the MCU handbook and do a Supernatural: Men of Letters period piece series, although it would probably have to have a set end date and actually stick to it. But they could do a couple seasons leading up to when Abaddon possesses Henry's partner, and then a season or two after filling in the gap before he jumps in time to meet his grandsons.
The rest of this post is from 2 weeks ago (7/30, with the suggested name of "Tran & Son"). I also wanted to try out the trick of changing the post date to get this to show up today but with comments from then (sorry to anyone who gets replies to 2 week old comments).
So far, it doesn't seem to have worked. At least not how I expected. It did move to the top of my posts list, but not on the O-Deck so I guess only the mainpage authors can pull that trick. It did work, but took a while to take effect.
I was watching tonight's Supernatural rerun and it was the episode Captives, which like any episode she's in, showcases just how much of a bad ass (Kevin's mom) Linda Tran is. So if Supernatural is trying to do a spin-off, why come up with some lame new characters that no one really cared about, when you've already got a fan favorite, assuming the actress is available.
Now that she's got Kevin back, albeit in ghost form, she can keep an eye out for demon or monster activity and help to make sure what happened to her or Kevin doesn't happen to anyone else. She'd be more helpful to them than Sam or Dean because she has more recent memories of what it's like to have a normal life, unaware of the demons, angels and monsters of the world. And since he's a quick study, I'm sure Kevin would be able to offer some ghostly help, with flying objects and stuff.
They could even meet up with previously seen characters like Castiel, Garth, or the boy and his golem.
ETA: I'd also like to learn if ghost Kevin is still technically a prophet, especially since Metatron blocked any other potential prophets from succeeding him. So can he still read ennochian? And if not, considering how smart he is, how much knowledge would he retain just from being Kevin?
And I would love a scene in this spin-off where a demon tries threatening Ms. Tran with burning Kevin's ring to get rid of his ghost, only to learn that she gave it a fire-retardant coating because she's smart like that.
ETA2: alternate suggested title: Kevin's Mom. The downside is that it takes away from the show mainly being about Linda Tran, but the quirkiness of the title could get more people curious enough to tune in for at least the pilot. Either title should be prefaced with Supernatural:
What Supernatural fan wouldn't watch a show featuring this awesome character?
**If anyone had previously already suggested this, sorry I missed it, I did a search here and io9's mainpage. Also, I completely agree with you.
As an aside, while looking for gifs that demonstrate her toughness, I learned that she played Ross' girlfriend Julie from one of the early seasons of Friends, and my mind is blown.