Kaleem Ali, 18, approached one of the women who gave evidence in the trial of his father Qurban and five others.
The victim said she had been left "shaking and in fear of her safety".
Ali, of Clough Road, Masborough, received a three-year restraining order at Rotherham Magistrates' Court.
He was also ordered to pay Â£360 towards the cost of the prosecution and given 12-week curfew requirement.
Qurban Ali, 53, was one of six people jailed in February for the "systematic abuse" of  15 girls. He was convicted of conspiracy to rape and jailed for 10 years.
Prosecutor Mark Hughes told the court Kaleem Ali approached the woman in March 2015 as she was in her car with her children.
He said Ali addressed the woman and one child by name and appeared to start taking photographs of them on one mobile phone while using another to make a call.
Reading from the victim's police statement police, he said: "I truly believe this male wanted to scare me and it worked. I was crying and shaking. I was scared he was calling for other people to join him. I had my children with me and I feared for my safety."
Mr Hughes said Ali had accepted seeing the witness but denied taking photographs and denied that his actions were intended to intimidate.
Ali's lawyer, Steve Smith, said his client had learning difficulties which left him unable to understand how people perceived him or his actions.
He said Ali had approached the woman as a result of a "chance meeting".

The 27-year-old's deal ties him to Warriors until May 2019, having joined in 2010.
Pyrgos, capped 18 times by his country, told Glasgow's website he had spoken with Dave Rennie, who will replace head coach Gregor Townsend next year.
"He told me about his vision for the club and his rugby philosophy and it's exciting," said Pyrgos.
"To have someone of Dave's quality coming in is brilliant for the club.
"I love everything about Glasgow Warriors and the club means a huge amount to me.
"This is my seventh year at the Warriors and winning the Pro12 two years ago has been the standout moment.
"I'm excited for the future here and we'll be working extremely hard to continue to compete for trophies every season. I believe we have a squad capable of doing that and that's the main reason I wanted to stay."
Townsend, who will become Scotland head coach next summer, added: "It's brilliant news for the club that Henry has signed for another two years.
"He is one of our leaders and has developed a huge amount in his time at the club. Now he is helping the club continue to improve and evolve on and off the pitch.
"There is a lot more to come from him on the playing side and we are really fortunate to have such a high quality group of scrum-halves right now."
The son of a man jailed as part of a gang who groomed and abused teenage girls in Rotherham has been given a 12-month community order after being found guilty of witness intimidation.
[NEXT_CONCEPT]
Scotland scrum-half Henry Pyrgos has signed a new two-year contract with Glasgow Warriors.