"composed smile" is a correct and usable phrase in written English.
It can be used to describe someone who is in control of their emotions and not showing them in public, usually in the context of trying to appear strong and confident. For example, "She offered a composed smile as she told them she was leaving the company."
"We just live together," she said, with a slight, composed smile.
"With her head ever so slightly bowed, but with a composed smile on her face, the 33-year-old, who was raised thousands of miles away in a humble South African family, looked like she had been born to the role".
She had some nice lines, was composed, smiled a fair bit.
Afterward, at a reception, she reappeared, now composed and smiling, engulfed in a pale-blue floor-length gown with puffy sleeves.
At one point in my visit, Sanaa — a composed, wryly smiling woman in a white head scarf — took the floor to describe a terrifying night raid by the police last year, just after the Tahrir protests began.
In contrast to the emotional final bow of Raf Simons, who made a teary appearance on the Milan catwalk last week after being dismissed from Jil Sander, Pilati was composed and smiling as he showed his collection of uncompromisingly hard-edged chic, with chainmail dresses and narrow silhouettes.
Right next to these ghostly old men in the street, stooped under the press of unknowable hardships and visions of the bloody madness of the past, though, there was a whole other Cambodia one composed of smiling and enthusiastic young people, most under 25.
After the plane landed, Clinton took a moment to compose herself, smile... and flip her hair.
The theme was taken up in two Charlie Chaplin tunes, the old Petula Clark hit "This Is My Song" (written for the film "The Countess of Hong Kong") and "Smile" (composed for "Modern Times"), sung back to back.
