She wanted to follow in the footsteps of her high-flying barrister father and was on the brink of starting a law degree that would have opened up a world of opportunities.

But instead Emily Bowen is beginning a prison sentence this week after a rivalry with another teenager from her orchestra led to a sickening acid attack at their school.

Bowen was jailed on Monday for putting drain cleaner in the viola case of love rival Molly Young, who was scarred for life when she went to get her instrument in the music room at Knox Academy, in Haddington, East Lothian.

It can be reported today that Bowen later wrote a fake poison pen letter in a bid to justify her shocking actions. 

The calculating move by Bowen took place six weeks after she had poured One Shot drain cleaner - containing 91 per cent sulphuric acid - into Molly's viola case. The corrosive liquid poured out of the case and onto 18-year-old Molly's legs as she took the instrument down from a shelf in the classroom. 

The girls, described as 'talented musicians', had fallen out when Miss Young began seeing Bowen's former boyfriend. Bowen was jailed for 21 months for the 'wicked' incident - which took place in September last year - at Edinburgh Sheriff Court on Monday.

The court had previously been told that the 18-year-old had penned the poisonous letter to herself and signed it with her victim's name. 

Fiscal depute Aidan Higgins said: 'On November 10 last year Emily Bowen prepared a letter which appeared to come from Molly Young in which she talked of Emily Bowen to kill herself.

'Subsequently Emily Bowen admitted it was she who was the author of the letter. Bowen, from Haddington, is the daughter of Andrew Bowen QC and a family friend revealed the teenager wanted to follow in her father's legal footsteps as she was due to study law at Aberdeen University.

But those career dreams are now over for the acid attacker as she will spend the next 21 months behind bars instead.

The friend said: 'Emily had been accepted to Aberdeen University to take a law degree. She is a very intelligent girl and she would have sailed through any degree she wanted to do.

'She has always looked up to her father Andy and I think it was a dream of hers to follow him in his profession.'

Mr Bowen sat beside his daughter in the dock when she pleaded guilty to recklessly and culpably pouring sulphuric acid into Molly Young's viola case during a court hearing in June.

Mr Bowen has in the past worked for the United Nations in a legal capacity in the Gaza Strip, Kosovo and the West Bank. 

Sheriff Michael O'Grady QC described the attack as 'utterly wicked', telling Emily: 'In the period leading up to these events you actually researched this topic.