"I always knew i was bi, i just thought it was bipolar," Max captioned her pic, which shows her sitting outdoors in the grass with a rainbow flag around her. Heather reposted Max's announcement and wrote her a sweet message.
"I love you my beautiful, hilarious, amazing child! I am SO proud to be your Mother ! ?️??️??️??️??️?," the 51-year-old reality star captioned her post.
ET spoke with Heather -- who left RHOC in 2016 after joining season 7 -- in February, where she talked about her children and some backlash she received after posting a photo of her 9-year-old daughter Coco wearing a tuxedo to a formal event instead of a dress. She told ET that, above all else, she would always support her children.
"So for me, I have four children and they are all very, very different, and my job as a parent is to create healthy, functioning, independent humans," Heather shared. "Whether those humans are straight, gay, bi, trans, they like to wear girls clothes, boys clothes, gender-neutral clothes, I don't care. That does not fall within what I am talking about."
"They need to be healthy, functioning, happy humans and I really think that Terry and I -- we are not perfect parents -- but I think we are doing a pretty good job," she continued. "So, when I post about Coco, she is just my daughter. I don't think about the fact that she is wearing a suit, not wearing a suit, that she likes to wear 'boys' clothes, whatever that is. I do think it is sad, some of the comments that we get back on social media. But, you know what? That is not my job to change everyone. I am in charge of my four humans, and we are walking a good path."