U.S. Rep. Gabrielle Giffords is likely to be taken later this week to a Houston hospital, “one of the best rehabilitation hospitals in the nation,” her spokesman said today.

Giffords is expected to move Friday to TIRR Memorial Hermann Rehabilitation Hospital in Houston.

“But because this is a fluid situation, the exact day of the move will depend on the congresswoman’s health,” added the news release from Giffords’ spokesman C.J. Karamargin.

 Mark Kelly, the congresswoman’s husband, an astronaut who lives in Houston, said he and Giffords’ parents weighed many factors in making the decision, including TIRR Memorial Hermann’s “relative proximity to Tucson and its outstanding reputation.”

The hospital has been named one of the top-rated rehabilitation hospitals in the country by U.S. News & World Report for 21 years, the news release said.

“I am extremely hopeful at the signs of recovery that my wife has made since the shooting,” Kelly said in the news release. “The team of doctors and nurses at UMC has stabilized her to the point of being ready to move to the rehabilitation phase. Their goal — and our goal — has been to provide Gabby with the best care possible. It is for that reason that we have chosen to have her undergo rehabilitation at TIRR Memorial Hermann, which has a national reputation for treating serious penetrating brain injuries and is also in a community where I have family and a strong support network.”

Giffords is the only victim of the Jan. 8 Tucson shooting who remains hospitalized.

The 40-year-old is in serious condition and officials with University Medical Center say she does not have a confirmed discharge date.

Eleven people were hospitalized at UMC after the shooting rampage, which occurred at a northwest side supermarket.

Giffords was shot through the left side of her brain.

The trajectory of the bullet was such that it stayed only in the left hemisphere and did not cross through the brain's geometric center.

The left side of the brain typically controls right-sided strength, sensation and speech, including the ability to understand simple commands — that's why doctors have been so encouraged that the congresswoman is able to understand simple commands, such as hand squeezes and showing fingers. Her husband has reported that she smiled, too.

Doctors have not given Giffords a prognosis for recovery, however.