Constance was born January 5th, 1992,1 during the Uranus Neptune conjunction in Capricorn. She's also a Capricorn Sun, so she's carrying quite a bit of Capricorn energy, as are many kids around her age.2
Without a birth time, only the planet in sign placements can be determined, which is unfortunate, but still so revealing. Constance has 4 planets in Capricorn, the Sun, Moon, Uranus, and Neptune, as well as her north node, all lined up in one big stellium cluster.3
A strong Uranus is a classic signature for rebellion, yet Constance has said sincerely in interviews that she did not intend to do it to be rebellious or cause an uproar, she simply wanted to be herself and go to her own school's prom, as she felt should be her right. "I'm not going to go to prom and pretend I'm not gay. There's no point"–she said in an interview on Ellen. With Uranus principles being such a core component of her identity, Constance's challenge isn't to rebel against societal pressure as much as it is to be independent of it, to be able to know what is right for who she is and assert that, live that truth. Rebellion happens on the frequent occasion that what we want isn't in alignment with what others want us to be, and we have to break from convention and disappoint and annoy others. But Uranus itself is pursuing your own Truth and your inherent human right to do so.
Neptune is conjunct her Sun on the other side, also rather closely, aligning her identity with a strong sense of idealism, and a consciousness pointed toward the highest and purest ideals. Neptune can also represent a place in our lives where our personal boundaries are low. Neptune is where we are open, spiritually, empathetically, and intuitively. Yet Uranus often represents where we have strong boundaries, even when we don't necessarily intend to, because our apparent and inherent differences from the mainstream become most obvious with Uranus' location in our chart (and the area of life that it's location represents). So we naturally feel a boundary, a distance from others, in this area of our lives.
With Neptune close to her Sun as well, and her relative youth and inexperience, there is a vulnerability to overidentifying with the ideal, what she's representing on a larger scale overpowering her own sense of self. She could get swept up into others' well-meaning plan for her by using her to push an agenda, which would be just as problematic for her, in a way, as it would be for her to have compromised her rights and personal truth in the first place by allowing authorities to tell her who she can and can't accompany to prom.