Josephine ‘Josie’ McFadyen, 25, was married in the first ever episode of the documentary and was also the first divorcee of the show on Channel 4.
She was allegedly joined by other family members, including mum Josie Doherty, 45, in assault on Eileen Doyle and her partially blind sister Margaret Doyle.
Some of the attackers stamped on Margaret’s head and stomach while one shouted: “Go on kick the baby out of her”.
Margaret Doyle was more than eight months pregnant at the time, Kingston Crown Court heard.
Also in the dock is Doherty’s daughter Barbara McFadyen, 22, son Isaac McFadyen, 19, and their cousin 21-year-old Charlie Collins.
“Some were stamping on her head. Others were stamping on her belly”
The five all deny violent disorder arising from the incident at the nail bar on High Street, Twickenham, on September 1, 2016.
The five family members had spotted the Doyle sisters as they walked past them and followed them into the nail bar on, Kingston Crown Court heard.
James Lachkovic, prosecuting, said: “These five defendants entered that nail bar and directed violence at two sisters of another family, Eileen and Margaret Doyle, who are also members of the travelling community.
“Margaret Doyle was over eight months pregnant at the time.
“There is no dispute that the two families know each other and that for a number of years there has been bad feeling between these two families.”
Eileen claimed she was so worried she might be attacked, she even removed her earrings before she was set up.
She then stepped in to defend Margaret who came under attack and was knocked to the floor, the court heard.
Mr Lachkovic said: “She saw Margaret on the floor with three people around her. Some were stamping on her head.
“Others were stamping on her belly. She focused on those attacking her sister.”
Mr Lachkovic added that Eileen heard someone shout: “Go on kick the baby out of her”.
The prosecutor said Margaret suffered from a number of “medical aliments” that affected her ability “to understand what was going on”.
Police arrived as the attackers fled in a vehicle, which was pointed out to cops by Eileen.
Jurors heard Margaret Doyle gave birth to a baby without any complications after the incident.
The prosecutor said while Collins and Doherty deny entering the nail salon, the three McFadyen siblings admit being inside.
He said: “Isaac McFadyen says that he was only in the shop very briefly but he was only there to protect his sister who was being attacked.”
Josephine McFadyen claims that initially she was outside the nail salon looking after children while others were inside, but when she went in she was attacked by Margaret Doyle.
He told the court that Barbara McFadyen claims to have been dragged into the shop by Eileen Doyle and attacked.
Josie Doherty, Josephine McFadyen, Barbara McFadyen and Isaac McFadyen, all of Hounslow Road, Feltham, deny violent disorder.
Collins, of Little Dale Road, Sheffield, also denies violent disorder.
The trial continues.