The 35-year-old child killer and paedophile is planning to marry when he leaves prison after he proposed last year.
Jon Venables' bride-to-be is fully aware that he murdered two-year-old James Bulger and has even been showing off her engagement ring.
When he was jailed for 40 months for downloading child porn in recent weeks, the fiancée stood by Venables, reports Daily Mail.
A source told The Sun Online: "Officials have made this woman fully aware of Venables" horrific crimes yet this hasn't stopped her wanting to be with him.
"You have to question what kind of woman would choose to spend their life with a convicted child killer and paedophile."
They added that while the couple are planning a happy life together, James had any chance of finding his soulmate snatched from him when he was killed.
Venables was forced to reveal his identity to his girlfriend when officials realised how serious the relationship was.
He told her how he and Robert Thompson murdered the two-year-old after abducting him in Liverpool in 1993.
Both were released on licence from a young offenders' institution in 2001 when they turned 18.
Venables was living with his girlfriend when probation workers found a laptop hidden behind a headboard in his room.
They discovered 1,160 child abuse images and videos. The Old Bailey was told that almost 400 fell in the most depraved category.
He was also found to have downloaded a manual on to abuse children. There is no suggestion his partner knew about what he was using the laptop for.
Though his girlfriend is childless, she has relatives with primary school age youngsters.
News of the engagement comes as a fresh investigation launches into leaked photographs of Venables, Mirror Online reports.
Prisoners are understood to have obtained pictures that reveal the killer's identity. The images are said to reveal his alleged new name.
They reportedly identify the prison in which he is serving his sentence for indecent images of children.
Branding him a "dirty nonce", the inmates say they want to "expose" Venables.
But if they did that they would risk two years in jail for breaching the anonymity order that protects Venables and Thompson. Both were aged 10 years old when they abducted James in Bootle.
The Attorney General's office said: "We have received complaints the anonymity has been breached. An investigation is ongoing."
There are fears harm could befall Venables or innocents wrongly identified as the killer.
It is thought he has been given as many as four new identities, with each reportedly costing £250,000 (NZD$478,963).