need help- how to stop my 3 year old from sucking her fingers

Dear sister @cha1
A Nice useful thread about common issue with many toddlers.
But my mother applied castor oil on the thumb on her grand daughter's right thumb while she with rest of fingers hold the long hair falling on her forehead blocking her vision from RT ight eye.
It helped a bit but when her thumb not smeared with castor her habit got restored.
A few months later sh ed was taken to swami malai for tonsure. After th he tonsure, she totally forgot that habit.
Now - she my daughter is nearing forty and delights seeing her black and white and colour snaps with her thumb sucking.
Your daughter must be 15 now and do let IL Folks know ultimately how she gave up th hat habit. Did you apply neem oil to make her cease that habit?
Agog yo know.
"Adaptable" is good to get enlarge your circle of friends and pays always rich dividends later in life if not now.
I trust link below on habits would be an enjoyable read .
You Know Habits Die Hard
Regards.
Best wishes