Grandma caught waving to 17-year-old granddaughter while she rides bus: 'We just love her so much'

— -- Never underestimate a grandparent's love for their grandchildren.

Rio Smith told her grandparents she was nervous ahead of her first job after high school.

The 17-year-old from Methil, Scotland, told ABC News after her grandparents -- Valerie and Wilson Ovenstone -- discovered the bus she needed to take to her new job rode right past their house, they knew what to do to ease her fears.

"Every day they'd get up and my grandparents would wave," she gushed.

A video of Valerie Ovenstone, 68, waving to Smith went viral on Twitter with more than 44,000 retweets.

The grandmother, who lives only five minutes away from her granddaughter, said it's the least she can do for Smith.

"Well, we just love her so much, we just wanted to wave to her," Valerie Ovenstone told ABC News. "We're very close."

The grandmother said it's "so sweet" that Smith recorded her waving last week. "I just couldn't believe it," she said with a laugh.