Alyson Sayers told Birmingham Crown Court her son Jonathan Houseman, who denies murder, was also kind and "that hasn't changed".
Brian McIntosh, 29, and Will Henry, 29, were both killed at the Albion Works industrial estate in Brierley Hill on September 30 last year.
Mrs Sayers had given her son around £175,000 – which equated to £250,000 with interest paid on credit cards – over the course of around 13 years, jurors were told.
But there had been a long-term understanding that Houseman would start to pay the money back when she and her husband went into retirement, a judge heard.
The witness told Birmingham Crown Court she gave him some money to him to pay off business debts, with someone threatening to kill Houseman, 33, on one occasion over a debt.
Mrs Sayers explained to jurors how at times Houseman would come to their home and was "upset and visibly distressed" and it was "difficult" for him to ask for money.
On September 30 last year, the day victims Mr McIntosh and Mr Henry were killed, Houseman had visited their home just before 2pm, the court heard.
Houseman had asked if he could use their caravan, which the witness and her husband agreed to, before he changed his clothes and then headed off.
Mrs Sayers, a former police officer, explained she had been "really busy" and so she had only "glanced" at him but he seemed "normal" and nothing seemed "untoward".
She had six missed calls the following day from Houseman's partner and had called her back at around 3.30pm, before she later left and arrived at the caravan park for around 8.20pm where she was met by police, she told the court.
Asked whether Houseman had exhibited any aggressive tendencies, Mrs Sayers said "no" and explained her son had been hardworking all of his life and had taken on two paper rounds, aged 13. She said he was "always the first to help" anybody in need.
Houseman, 33, of no fixed address but formerly of Quarry Park Road, Stourbridge, denies murder.
Co-accused Richard Avery, 33, of no fixed address, whom the Crown have said was part of the “planning and preparation” for the killings, also denies murder and perverting the course of justice.
Avery’s partner, 33-year-old Francesca Scott, of Lower Valley Road, Brierley Hill, is also on trial accused of perverting the course of justice after allegedly disposing of clothing or other items.
The trial continues.