Japan?s Crown Princess Masako took part in an increasing round of official duties on Monday, a sign she is gradually recovering from a stress-related illness that kept her mostly out of public view for the past two years.

Masako, a Harvard-educated former diplomat, joined Emperor Akihito and other imperial family members on a palace balcony to greet thousands of well-wishers, many of them waving Japanese flags, in a traditional New Year?s rite.

Dressed in a long-sleeved ivory suit, Masako, 42, smiled and waved during three rounds of the greetings, up from the one round she took part in last year. On Sunday, she attended a New Year?s ceremony at the palace for the first time in three years. Masako?s doctors last month said she was making progress but urged patience, noting that physically she still had ups and downs and her condition was easily influenced by mental and physical stress.

Royal watchers have said pressure to bear a male heir was a key cause of Masako?s illness. Masako and her husband, Crown Prince Naruhito, have one daughter, Aiko, who turned four in December. Under current law, only males can ascend the throne, but the government plans to submit to parliament this year a bill that will give women equal rights to do so.