Patients have the right to refuse medical treatment, and it is not considered assisted suicide, else the law permitting refusal is meaningless - you're not going to find any court in any state that accepts arguments based on the notion that a particular law is inherently meaningless and without effect. In this case, that refusal came via her legal guardian. If you don't like that outcome, and I sense you don't, then perhaps the laws on guardianship should be changed in Florida.
Or perhaps judges should bring forward guardianship cases once they've been filed. This judge sat on that case for over two years. It was filed in Nov. 2002.