Spoiler, it was staged and the video was cringey.G proposed in a forest
Andrew also proposed in a forest! (I didn't see this video because it looked staged in the thumbnail, bit I wish I had watched it now.)
In her new vlog she mentioned again how she's done this stuff before. Even if that's at the back of her mind I'm not sure it's helpful to anyone for her to keep bringing it up. It won't be making G feel good, her family already know, her viewers who already know/ remember are fully aware and those who (somehow!) weren't aware of her previous engagement will potentially just ask questions. If she's talking about it for herself then I hope she's talking to a professional to unpack her feelings. Bringing up her first engagement this regularly can't be healthy or useful, focusing on the current wedding planning will be more enjoyable without thinking about your past relationship. (I'm aware it isn't that easy when you go through something upsetting or traumatic but we need to process things in the appropriate way and sometimes that might be chatting to a professional instead of casually mentioning things in a YouTube video).