"I have always had many friends in the LGBTQ community and still I wasn't sure what steps I should take as his mother, or even what an appropriate response was outside of 'I still love you'. How do I tell people, how do I say this is my son and I'm proud that he has the courage to live his truth, how do I set the tone in our corner of the universe for his journey to be as smooth as possible?"
Her beautiful solution was a belated "gender reveal", a photo shoot to announce to the world that "it's a boy".
There's a fake belly, blue balloons, a heap of blue glitter and a very funny snap of her "baby" all wrapped up in swaddle.
"When your child comes out as trans, the best thing to do is create a photo shoot to celebrate the fact that he silently and bravely stepped out of the race that he never wanted to be in, found his own lane and proceeded to win," Ms green wrote.
"HAPPY 20TH BIRTHDAY, Adrian! You are without a doubt the most fascinating human I know, and I will always be your biggest fan! I love you, I honour who you are, and I respect your courage to be unapologetically you!! Let's celebrate!!"
The photos have since gone viral and have been shared 16,000 times and counting. And their message, she says, is one of joy.
"It is not enough to accept or 'put up' with the Transgender community," Ms Green says. "We need to celebrate them. These men and women have had courage that is beyond anything we can fathom. The strength they possess to not only come out to themselves but to share their truth with a largely unaccepting world is profound!"
But behind the celebration, the proud mum wants to draw attention to a serious issue. "I couldn't help but think that my son being trans just statistically increased his risk of suicide," she wrote. "I think most people have heard that 40 per cent of transgender people will attempt suicide. Regardless of the facts and figures this is simply not a risk I was willing to take."
While acknowledging that "outing" her son so publicly could also be dangerous, "because of all of the hate in the world" Ms Green notes that the experience has been empowering for him - and has only strengthened his resolve.
Ms Green also issued some advice for other parents.
"First of all, the heartbreaking part of this story is that it is 2019 and we are celebrating a mother's unconditional love for her child. I am not sure how other parents raise their children, but I thought this was a given." She urged parents to trust their kids, respect them and "accept that you don't know everything there is to know. Let them teach you."
Ms Green highlights that as parents, we often say "I want to make the world a better place for my children." "So go do it," she writes. "This isn't just a tagline for recycling. It should be a way of living. Change the world, celebrate your child, love and support your neighbors…. we can call it humanity!"
And finally, she says, demand that people honour and respect your child while understanding that there will always be people you can't "influence or educate".
"Those people are not your people!!" she notes. "Don't dwell, don't worry about what they think, our kids are watching us, and we have a tremendous community of individuals that are our people!"