A rep for the 23-year old stated at the time: "Frankie is still ill and she's taking her time to recover. Under doctors' orders she is only permitted to attend tour rehearsals. She's easing herself back in to things with the group but will be appearing on the tour which starts at the end of this month."
Now, Frankie has broken her silence regarding her suspected illness, telling Glamour magazine that she took a break from The Saturdays in a bid to battle her ongoing issues with depression, which caused her to suffer panic attacks and stop eating.
Sandford confessed to the publication: "I felt that I was worthless, that I was ugly, that I didn't deserve anything. It all started when I was about 15 or 16. I used to stay in bed a lot and had no motivation; I thought I was just being lazy.
"Since childhood I've been an over-thinker. I used to make myself sick with worry. I'd always have stomach aches and breathing problems."
She continued: "I didn't do anything about it until it got to the stage when I was just coming home and going straight to bed. I wouldn't have any dinner, I couldn't talk to anyone."
Frankie went on to reveal that she realised her problems were getting worse after throwing a fit at boyfriend footballer Wayne Bridge for buying her the incorrect yoghurt.
The My Heart Takes Over singer explained: "Suddenly my illness had control over me. I got upset because Wayne hadn't bought the right yogurts; I managed to convince myself he didn't know me at all.
"It set off this spiral of negative thinking – if I disappeared, it wouldn't matter to anyone. In fact, it would make everybody's life easier. I felt that I was worthless, that I was ugly, that I didn't deserve anything.
"I had some counselling which helped for a while but then I stopped going when I felt better. There was a part of me thinking I was putting it on, that I wasn't properly sick, and only sick people should be in hospital.
"I thought that since mine was only a mind thing, I should snap out of it. I got so good at covering it up, I didn't confide in anyone."
Frankie added: "I thought I was selfish, miserable and ungrateful. I'd been given this amazing life, but I wasn't happy.
"I did lose myself, but I feel like me again now. But I try not to put pressure on myself – it's unrealistic, no-one is 100% happy all of the time."