A US congresswoman shot in the head two weeks ago moved to a Houston rehab centre yesterday where her husband hopes she will continue on the path to a full recovery.

Democratic Rep. Gabrielle Giffords has been making progress nearly every day in her recovery from a bullet wound to the brain.

Doctors ticked off markers of her continuing improvement: She scrolled through an iPad, picked out different coloured objects and moved her lips.

They are unsure whether she is mouthing words, nor do they know how much she is able to see.

Staff at University Medical Centre in Tucson took Ms Giffords to ­­­­­a balcony at the hospital, where she breathed in the fresh air and felt the sun, trauma surgeon Peter Rhee said.

“I saw the biggest smile she could gather,” Mr Rhee said. “We are very happy to have her enjoying the sunshine of Arizona.”

Her husband, Houston-based astronaut Mark Kelly, believes she has tried to speak and can recognise those around her.

“I can just look in her eyes and tell,” Mr Kelly said at a final briefing at the hospital. “She is very aware of the situation.”