Zainab al-Hilli's health is understood to have improved in recent days, allowing her to travel back to the UK.
Zainab left France this morning at around 8am. Police from Britain accompanied the little girl.
Brett Martin, the first witness who found the British family in the Alps has described the moment he came across the attack.
A friend of the al-Hilli family has said he believes he could assist the investigation into the fatal shootings of the three family members.
A previously unreported witness has told a French paper how he came across the aftermath of the killings of the al-Hilli family in the Alps.