She lives, even though everything she knows about medicine says she died a world away and she's left a daughter behind and some heartbroken friends.
She can't ever go home, and she knows that, too. The sanguine vampiris in her veins will ring out like a shot and she'll never see anything outside of a lab at Area 51 for as long as she lives.
Helen tells her that'll be a long time, so she never goes back, and years go by.
She keeps track of her friends and lovers, former and potential, from a distance. She sees them buckle to inevitability and expectations. She even sees a few find happiness. It's nice in its own way, even if she wishes she were there.
She watches Cassandra graduate from high school, from college, from med school. One day, she attends her wedding at the chapel where Janet married her first husband. The marriage was a disaster but the wedding day, for Janet, had been a dream come true. Genetic relation or otherwise, Cassie is her daughter at heart.
She spends years toiling in the bowels of the Sanctuary, helping and healing and doing what she can. Her years with the SGC come in handy and she can name a dozen biologists--alive when last she heard--who would kill to see the subjects and specimens that she converses with in the day to day. The humanist and Abnormalist in her comes to love them all; no less the woman who took her in and saved her life.
She doesn't pretend she knows why, but something familiar in the woman's face gives her pause. It always has; she's an echo to Janet, a reproduction of someone beloved, though she existed long before. Janet can't help the way she feels, but she tries because Helen deserves no less.
For that reason, she lingers when Ashley and Henry are taken by the Cabal. She knows how Helen loves her daughter and the man who may as well be her son. She understands a mother's desperation and fear; she doesn't pity them anymore than she pitied Adrian Conrad, Nirrti, or the Trust. They have this coming to them.
She's still there when Ashley turns into a Trojan horse and their greatest threat. She sees in the security footage nights later how Helen couldn't bear to defend herself against her own child. Better to die by her hand than take her life, she thinks. Something else she understands.
Then, Ashley's gone and all that's left is rose color and mist. Janet imagines that Ashley understood more about devotion and sacrifice than her mother would have given her credit for. She still echoes Helen's sentiment and puts white roses on her empty casket. She'll have outlived Cassandra someday, so she considers it a morbid kind of practice.
When Helen's denial loses touch with the bounds of science, she taps the good Dr. Zimmerman to bring Helen back down because she can't. She wants Helen to find what she's looking for since, deep down, she's looking for the same. Longevity isn't all it's cracked up to be. General Hammond died not long ago and Janet knows that's only the beginning of her permanent losses. (She'd thought Jacob and Selmac's deaths were hard to swallow. Hammond's is far beyond that.)
When the world is devoured by chaos, Janet is prepared. This was once her life, now it's everyone's. She works around the clock at Helen's side because she can. She's there when Henry falls, when the Big Guy succumbs, and when there's really no more reason for them to stay. The immunity that shields Helen is shared by the blood that resurrected Janet. Together, they're magnificent and that sensation of belonging feels like home.
Heads bowed together over the telescope and words longer than a single breath battling for dominance as they both have the same epiphany; it's amazing, it's kismet. It's home. That's how she knows it can't last, this quiet second chance. She's right and that's an old feeling, too.
She covers Helen's six on the ground in Buenos Aires, there to help evacuate Abnormals while there's still time. (For the first time, there's so little of that.) But the fear is bigger than they are and their forces are too few. The military is terrified of what this place will become and Janet knows what happens in those circumstances. She fights beside Helen for every person they can save anyway, because they're doctors and they can no more do harm than leave someone behind. Janet learned that lesson well from a certain colonel she used to know.
John Druitt doesn't find them in time to pull them out before the tactical nuke falls. Janet hears its war cry, feels its impact, and sees the shockwave coming before its born. One hand is wrapped around a modified P90 and the other is touching Helen. There are worst last things to touch.
Looking at one another, eternity stretched behind Helen and truncated before Janet, she realizes they're thinking the same thought, Does this mean we win?
She never does get an answer.