She has said: "If you cut me open, I would bleed BBC."
Says her media profiles: "You're unlikely to see her on any other channel." But, then, just a few months ago, she also said she was "very, very happy" with her partner of 15 years. And we believed every word, because the smart, sexy Strictly star and Breakfast TV stalwart, whose commitment to the Beeb was only outshone by her commitment to her close-knit family, seemed to be the epitome of the uncomplicated, straight-talking, have-it-all mum and career woman.
Some of us set our kitchen clocks to Susanna Reid's inner-psyche, it was so reliable and unchanging. So it knocked everyone for six when, in the course of a week, she hit us with not one, but two shocking U-turns. She's moving to ITV. And she's split from her partner. Seems like Susanna likes to keep us on her toes, that ducking, diving, bobbing and weaving little minx.
The relationship bombshell came first. There were murmurs that Reid and her partner, charity director Dominic Cotton, were going through a rocky patch. But we, her adoring public, refused to believe them.
If Reid herself hadn't always been such a self-contained, sure-footed person there might have been more cynicism about her statement that, in spite of the 3.30am starts and thrice-weekly 415-mile round trips BBC Breakfast's move from London to Salford had forced upon her, her relationship with Cotton was as strong as ever.
Instead, her decision to make that regular commute, so that she could read bedtime stories to her three sons and spend a few hours with Cotton rather than just disappear for five days, was seen as evidence of their continuing closeness.
She gushed about his great skills as an attentive, patient dad and said he was "unrivalled as a parent". If it wasn't for his support regarding her work move to Salford, she said, she could never have done it. But, gosh, it had all worked out so brilliantly.
She almost made it sound like the ideal template for a successful family life. A superstar mum, a housework-honing dad, 1,200 miles of commuting a week – what could possibly go wrong?
Maybe it was the endless journeys, the squeezed hours, the fatigue, or the pressure to be on form for every stolen moment which took its toll on the perfect couple.
Maybe Reid's unwillingness to marry Cotton, whom she admitted was keen to tie the knot, rankled more than either of them realised. Maybe Reid stopped finding the one-liners from her "best friend", who "still makes me laugh so much" ("such a key part of why it works") quite so funny after three hours on a train.
Or maybe it was simply the Strictly curse. Already an immensely popular Breakfast show host and famously dubbed "the sexiest thing to come out of Croyden since Kate Moss", Reid's profile sky-rocketed when she took part in Strictly Come Dancing at the end of last year.
Although her dancing prowess was regularly questioned by the judges, who were booed by the Susanna-loving audience for handing her some mediocre scores, she was the bookies' 3/1 favourite to win before the final.
It was evident that Reid had that quintessential quality that can't be taught and can't be bottled, but is gold dust to live TV producers; likeability. Buckets of it. It got her the public votes to secure her mediocre moves a place in the final, and saw a plethora of Reid appreciation websites launched during her stint on the show.
In the end she was pipped at the post by the Amazonian Abbie Clancy, but it seems neither that, nor Fiona Fullerton's menacing accusations regarding Reid's "Obama-style use of social media and lack of charm", had much impact on her wider popularity.
Just a month later she was voted Radio Times' readers' favourite BBC Breakfast's presenter ever – and she won by a landslide, with more than half the votes cast. It appears FHM's 96th Sexiest Woman is just as beloved by families as she is by red-blooded males.
But, while the contest put her profile through the roof, it's also likely it tested her relationship with Cotton. No man likes to see his other half rubbing herself up against a fit, hunky man half her age, however convincingly he may plaster on a "supportive" smile when he's asked about it on live telly.
The show has a history of breaking up happy couples – Natasha Kaplinsky, Joe Calzaghe, actress Ali Bastion, and Countdown's Rachel Riley are just some of its victims. Were Reid and Cotton simply the next in a long line?
Whatever the tipping-point was, the couple's split remained a rumour until Cotton popped up on dating site match.com, declaring himself "separated" and inviting potential mates to admire his best feature – "my bum". The 46-year-old ex-BBC sports journalist's profile says he is "a sensitive soul", who "doesn't shy away from commitment".
"Life is for living with someone special," he declares, which must be a tough read for his now ex-partner, especially as they have three young sons to share the care of. What possessed Cotton to make the split public in this way no one knows, but it is a bizarre and sad way for a 15-year relationship to end.
No matter how happy Reid once was with her family set-up, however, one thing about her has never been in doubt; she is very ambitious – unapologetically so. She only secured her main daytime slot hosting BBC Breakfast because she was willing to take on that treacherous commute; Sian Williams, who held the post before her, retreated in the face of Salford.
She has spent years steadily climbing the BBC ladder, from her first days at BBC Radio Bristol through 5Live, and News 24 on to BBC Breakfast. With the added momentum awarded by the Strictly gig, she really did have the world at her feet. She could have gone anywhere. And she's decided to go to ITV.
Who can say why the woman who never missed a chance to trumpet the wonders of the BBC has finally opted to jump ship? Is it as simple as the rumoured £1m contract? Or is there also something which appeals to the newly single Reid about making a clean break?
She may be photographed laughing in the tabloids above a caption which implies she doesn't look like she's heartbroken. But she took time off BBC Breakfast after allegedly struggling to cope with the fall-out of her separation. The truth is that no one comes out of a 15-year relationship with the father of her children without profound emotional distress.
Moving to a different channel, working on a brand new show – ITV is axing the disastrous Daybreak altogether – might be Reid's way of escaping old, sorrowful associations. A radical version of a holiday and a new haircut.
Yes, it might have felt even fresher if the new show hadn't been called Good Morning Britain, a name dredged up from the late-80s. But, still, ITV are taking a big step and for Reid it's a whole new world.
It also means an end to the gruesome commute (much as she loved Salford, you understand). Pastures anew, unknown territory, new faces – all might help Susanna Reid rediscover the easy contentment she had before fame, success and the ghouls that often accompany them crashed into her life.