TUCSON - Rep. Gabrielle Giffords continues to make progress in what doctors here described Monday as a miraculous recovery after undergoing a minor procedure over the weekend to repair a fracture in her right eye.

The Arizona Democrat apparently recognized her husband, gave him a smile and rubbed his neck for 10 minutes, which doctors at University Medical Center said is a sign that her higher cognitive abilities were preserved after she was shot through the head Jan. 8 in a rampage that killed six people and wounded 13.

With doctors preparing Giffords for the rehabilitation stage of her recovery, the discovery Monday of a little-known statutory provision in Arizona law raised the prospect of a legal complication that, if left unamended, would endanger her hold on her seat.

A statute buried in state law says that if a public officeholder ceases to "discharge the duties of office for the period of three consecutive months," the office shall be deemed vacant and that at such time, a special election could be called to fill the opening.

But in Washington, lawyers quickly concluded that the statute does not apply to members of Congress. The U.S. Constitution provides the qualifications for service in Congress and makes the House the sole judge of those qualifications.

Courts have consistently held that states cannot add qualifications to those in the Constitution and have rejected efforts to remove members of Congress, even through term limits and recalls.

"Legally, it's not a close call," said Brian Svoboda, a lawyer for the Democratic Party. "You have a history of interpreting these constitutional decisions and the courts have consistently struck down state laws that have tried to impose additional qualifications beyond those that are set forth in the Constitution."

Paul Bender, a constitutional scholar and a former dean of the Arizona State University College of Law, said that any determination of a vacancy would have to be made by Congress.

"The state has no right to say what the duties of a congresswoman are," he said. "The state has no right to say when the office becomes vacant."

At the hospital where Giffords is listed in serious condition, doctors said they are using a feeding tube to provide her with adequate nutrition. They said she is breathing on her own through a tube in her neck.

Doctors told reporters that Giffords still faces the risk of infection, pneumonia or other serious complications but that she made it through the most critical period in which her brain could swell.

Giffords underwent a two-hour procedure Saturday to repair a fracture in her right eye because bone fragments were pushing down on the socket. Surgeons said they made an incision in her eyebrow to remove the rim of the socket and removed bone fragments, taking pressure off the eye. They reconstructed the skull area using metal mesh.