What's the Real Age of Maturity?

In September of last year, 17 year-old Cassandra C was diagnosed with Hodgkins Lymphoma but steadfastly denied chemotherapy treatment. Even knowing that the chemo would give her an 80-85% chance of survival (without chemo she will only live 2 years), Cassandra stated that she "does not want poison in her body." Seems simple - she, now only six months away from legal adulthood, should be able to make choices regarding what goes into her own body, right? Not to the Connecticut Supreme Court. In December, after a failed attempt at court-ordered chemotherapy, the Connecticut Department of Children and Families (DFC) took Cassandra from her home (and her supportive mother) and put her in a closely-monitored hospital room. Citing her youth and her mother's distrust of physicians, the DFC claims it has the right and duty to remove a "child" from the care of a parent who's medical decisions, without intervention, would put the child's life at risk.

What's interesting is that the DFC hardly regards Cassandra's decision as her own, saying that she lacks the maturity for it. But how can her youth (and supposed immaturity from it) be a factor in her ability to consent when, for those her age and younger, it is seemingly disregarded? 17 year olds can choose to enlist in the army and donate blood. 16 year olds can get drivers licenses. 12 year olds can be tried as adults. It's clear that there is no defined line that determines when someone can make heavy life decisions. According to Cassandra's lawyer, "you don't go to sleep a 17-year-old knucklehead and wake up an 18-year-old sage."

In the hearing being held tomorrow regarding Cassandra's rights, the major question will not be whether or not it is logical to be treated with life-saving chemo, but when does she truly earn the constitutional right to deny it? And how much should this major decision be respected when it's coming from a "minor"?