Kathryn Roach is said to have left the boy in 'no doubt of what she would like to do or what she wanted him to do to her'.
Roach targeted the boy after he and some other students came into possession of her mobile phone and programmed their telephone numbers into it.
The teacher then sent a series of lewd texts to a pupil, suggesting they should meet, and outlining what she would like to do to him.
Roach - who admits sending the messages - was arrested and suspended once the school became aware of the texts.
David Clarke, prosecuting, told the court that Roach had abused her position of trust even though she had not met the pupils outside of school or entered into sexual activity with them. He said: 'Sexual activity didn't take place. The extent it would have gone to is hard to tell.'
Mary McKeone, defending Roach said her client 'accepts' she 'incited' the child to 'engage in sexual activity'.
Adjourning sentencing until October, 31st, Judge Stephen Everett said: 'She was the boy's teacher and had sent him a substantial number of texts which, at least in part, became more sexual in nature. She is a teacher in a position of trust being in contact, in this way, with a pupil.'
He told Roach she must sign the sex offenders' register, and warned her she could face a custodial sentence.