I question that. The ninth amendment says "The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people."
The Constitution doesn't specify how those unenumerated rights become recognized, but I don't see that it rules out such by the courts. The legislature doesn't seem to be the correct place because it should be based on a petition from the people who already own these rights.
I've often wondered how the founders envisioned these rights becoming identified and honored.
The rights referred to in the 9th Amendment were rights that existed at that time, in 1789. They were saying, basically, that if they left anything out, it was "retained" by the people. Not that rights that did not then exist could be created willy-nilly by the courts out of thin air, but that rights that the people already had would continue to be recognized.
Abortion, gay marriage and the right to a taxpayer paid lawyer were not rights that existed in 1789, to give three examples. They were created by judges acting in a legislative capacity.
The way to recognize a right not referred to in the Bill of Rights would be to assert it in a court of law, and then cite precedent for it. American law accepted the precedents of English common law up to the time of the founding, and then separated at that point. After that point, the only principled way to create a "right" was through legislative action, an action taken by the elected representatives of the people.