Fashion designer Beckham, 38, who reunited with the girl band in London on June 26, came under fire from critics for failing to smile at the 'Viva Forever' musical launch, reported Daily Mirror.
"It's annoying when people say Victoria wasn't smiling or didn't want to be there. She really did. It was a flying visit and both her and Melanie (Brown) were exhausted as they'd flown in from Los Angeles.
"She was so tired but, among us, she was on great form. It's great that she decided to make the trip at all. She's a very busy lady and in the middle of designing a new (fashion) range. It's certainly not easy for her," Mel C said.