The family visited the tourist attraction while in Canada and the singer's father took the opportunity to propose to her mother.
Lorde shared happy news on Monday, June 16, saying she had finally seen "a diamond in the flesh." Her parents, Vic O'Connor and Sonja Yelich, got engaged after 30 years together.
"BEST DAY," Lorde tweeted on Monday night. "Went to Niagara Falls - my dad proposed to my mum after almost 30 years together." She added a bunch of emojis such as heart, diamond ring, rose and smiley faces at the end of her tweet.
She would later make a reference to her hit "Royals" which has the lyrics, "I've never seen a diamond in the flesh / I cut my teeth on wedding rings in the movies / And I'm not proud of my address / In a torn-up town, no postcode envy." She tweeted, "Inevitable response yes I know I have seen a diamond now."
The family were in Canada where Lorde performed at the 2014 MuchMusic Video Awards in Toronto on Sunday. She took home International Video of the Year for her hit song.