The star’s 18-year-old sibling died of a suspected heart attack after collapsing outside her home in Earl’s Court, London last month.
Her death comes nearly two years after their mother, Johannah Deakin, died of leukaemia at the age of 43.
The Doncaster-born One Direction star took to Twitter yesterday to thank fans for their “lovely words” and confirmed he is turning his focus to music.
"Just wanted to thank everyone for their lovely words over the past couple of weeks," he tweeted.
“Back in the studio today to vocal something I wrote a few months ago. Sending you all loads of love x.”
The singer’s tweet comes after Tomlinson’s 20-year-old sister Lottie paid tribute to their sibling in a heart-breaking post to her “best friend”.
She shared a string of snaps of Félicité on Instagram and wrote: “My Fizzy, my baby sister, my best friend. I’m incomplete without you, I’m empty. I can’t picture my life without you.”
“I wish we could have lived life together for a little longer. Mama needed you and you needed her, you’re finally together again. I love you always, Dotty x.”