Millie Bobby Brown's Engagement Sparks Debate About Her Age

Stranger Things star Millie Bobby Brown is engaged at the age of just 19, an announcement that has evoked a huge reaction online.

Celebrities and social media users alike are commenting on the news that teenager Brown intends to marry Jake Bongiovi, 20, son of rock star Jon Bon Jovi. After the news broke, the phrase "She's 19" started trending online, as people expressed their shock at the news.

The Enola Holmes actress announced her engagement to much fanfare on social media, attracting thousands of messages of congratulations.

The likes of Paris Hilton and Sam Claflin offered their best wishes, while an old comment from Ariana Grande resurfaced online after the announcement.

Brown and Bongiovi appear to have been together for three years, which the actress highlighted in her announcement post on Instagram.

"I've loved you three summers now, honey, I want 'em all," Brown said, quoting Taylor Swift lyrics on Tuesday, as she announced her engagement to her 63 million followers. An attached black and white picture featured Brown and Bongiovi together, with Brown wearing her engagement ring.

Bongiovi referenced the big news too, sharing pictures of him together with Brown, writing "Forever."

Enola Holmes co-star Claflin wrote "congrats little sis," while reality TV royalty Hilton said, "congratulations beautiful." Over on Bongiovi's post, his uncle, Matthew Bongiovi, said "congrats nephew" while Stranger Things star Jamie Campbell Bower, who plays Vecna, simply left love heart and fire emojis.

After news of Brown's engagement spread online, fans started to compare the lives of celebrities during their teenage years. While Brown, who has been famous since she was 11 years old, is now engaged, an old comment of Grande's resurfaced.

"I wasn't even allowed to leave my house til I was 20," Grande wrote on Instagram to Brown a number of years ago.

While Brown did receive many messages of congratulations, others questioned her age.

"Ur like 12," "isn't she 10?" and "You are just a child for god's sake" were some of the messages on the comment section of her engagement post.

British journalist Emma Kelly made the point that the Stranger Things actress could be set for a potential name nightmare.

"Don't think I can cope with Millie Bobby Brown now going to be called Millie Bobby Brown Bon Jovi," she wrote.

With "She's 19" trending, some Twitter users have used it as an excuse to dredge up old banal tweets that they sent when they were 19.