A teenager charged with terrorism offences over her alleged plan to fight with the PKK (Kurdistan Workers Party) in Turkey reassured her family she was happy and made the right decision in a letter, a court has heard.

Silhan Ozcelik, 18, of Highbury Quadrant, was charged with engaging in conduct in preparation for terrorist acts after she was arrested at Stansted Airport in January this year, where she had returned from Germany.

Miss Ozcelik travelled to Brussels on a one-way Eurostar ticket in October 2014, four months after dropping out of college.

She left behind a letter for her family, which informed them she had joined the ranks of the PKK - a proscribed terrorist organisation under UK law.

It read: “Believe me this is the right thing for me to do. I am so happy right now that I have become a militant.”

In a 25-minute video in Turkish, she told her family: “My fight, my struggle is not just for the Kurdish people, it is for all people, for all women.”

She added: “It must not be misconstrued. This is not a Kurdistan matter. Even if Kurdistan is established today I will not return.”

Miss Ozcelik said she had thought about the decision for many years and could have become a lawyer, jurors heard.

In the video, she said she saw herself as a fighter and it was up to the PKK to decide how she would be used.

Miss Ozcelik, who has pleaded not guilty, was interviewed at the Southwark police station the day after her arrest and answered “no comment” to all questions.

On the opening day of a three-day trial at the Old Bailey, prosecutor Dan Pawson-Pounds warned the jury the case was not about Kurdish independence in Turkey.

He said: “This trial is not about who is right and who is wrong in either Turkey or Syria, and you are not being asked to return a verdict on the political situation in either country.”

Judge John Bevan told jurors there was a real danger of unfair prejudice in the case due to the terror attacks in Paris, which had “nothing whatsoever to do with the case we are about to try”.

He said: “If any of you have any connection, direct or indirect ... then I’d like you to say so now in case there’s a danger you feel you might be able to exercise an independent judgment.”

No juror declared any concern.

She is the youngest of four children - two girls and two boys. Her parents were originally from Turkey and she was born in London.

When asked whether he recalled seeing any PKK material in her bedroom, Miss Ozcelik’s brother Engin replied: “It was not PKK, it was more women’s rights posters.”

He said she was “looking after herself very well” and suspected that she may have had a boyfriend.

Mr Ozcelik agreed that in his family’s culture it was difficult for young women to meet men, and a relationship would be something she may have hidden.

He said: “Because of the way we view relationships in our culture, it would be more you meet someone and you get married to someone immediately.”

Under questioning from defence lawyer Peter Rowlands, Mr Ozcelik agreed it would have been “absolutely out of the question” for his sister to travel through Europe alone.

The trial continues.