Paul Walker’s mum is “very proud” of her two sons for helping their late brother’s last film to finish. Cheryl Walker said that while it was “bittersweet” for Caleb and Cody to film “Fast & Furious 7,” they are happy to do it for Paul.

In April, Caleb, a 36-year-old restaurant owner, and Cody, a 25-year-old paramedic, were announced to join the latest instalment billion-dollar film franchise to help complete Paul’s scenes.

Paul, who held the role of Brian O’Conner since the first film in 2001, already completed most of his scenes for the latest film before he was killed in a one-vehicle accident in November.

The production went on hiatus to give the cast and crew time to grieve their beloved member’s death.

After a few months, though, the production is back up, and Caleb and Cody were announced to share Paul’s role.

“[I’m] very proud of them,” their mother, Cheryl, told E! News. “It is bittersweet for them to do this. They are happy to honour their brother and finish the project.”

Cheryl added that her sons have been welcomed warmly by everyone on set, and are having a wonderful time.

Paul already shot his dramatic scenes and most of his action sequences for the film, though there are still minor ones that need to be filmed.

Cody has previously spoken up about Paul’s untimely demise, telling the Associated Press in an emotional interview that “it still doesn’t feel real.”

“Because sometimes, working in this industry, making films, he’d be away from his family three, four, six months at a time, you know. And my only interaction would be a phone call. So I know it’s going to take a while. It’s going to take a few years before it feels real.”

The brothers are only helping out the film to finish shooting scenes, but they are not embarking on a Hollywood career after this is over. Their sister, Ashlie, told RadarOnline.com in a separate interview that Cody and Caleb’s acting gig is just temporary.

“They’re not actors. This is just temporary,” Ashlie told the Web site. “They just want to help complete the film because so many people were so invested. Paul was invested. Both have things about them that are so similar to Paul, even the way they walk. It was a natural decision.”