Baroness Thatcher's condition has been described as "a lot brighter" as she continues her recovery from flu.
The former prime minister was admitted to Cromwell Hospital in London four days ago and staff expect her to remain there for "several more days".
"She is a lot brighter. She is sitting up in a chair in her own room now," the spokesman said.
Ill health prevented her from attending her 85th birthday celebrations at Downing St nine days ago.
The event went ahead without her, with Prime Minister David Cameron reading out a message of regret from her to the 150 guests.
On the advice of doctors, Lady Thatcher, who has previously suffered minor strokes, rarely speaks in public, but still attends public functions.
The hospital spokesman added: "She is making good progress and the situation continues to improve. She is more talkative and is moving around more freely."