According to Lombard, the paintings were on display in the apartment, in full view, but security precautions had been taken to protect the works.
The thieves removed Maya with Doll from a wall while the Jacqueline portrait was cut out of its frame, said the lawyer.
There was no sign of forced entry, according to police, who said the investigation had been handed over to the Paris police's organised crime division.
Completed in 1938, the painting is one of Picasso's classic oil paintings done in bright shades of green, blue and red and depicting young Maya in pigtails cradling a doll dressed in a sailor suit.
The stolen work of Jacqueline is from 1961, the year that the couple were married, and rates among the "most beautiful portraits" of Picasso's second wife, said Lombard.
Targeted by thieves
Maya was Widmaier Picasso's mother, born to Marie-Therese Walter, who was Picasso's companion during the late 20s and 30s. He was then married to Olga Khokhlova.
The Spanish-born artist who adopted France as his home painted scores of portraits of Jacqueline Roque, whom he met in 1954 and with whom he spent more than 20 years.
Picasso's works, among the world's most valuable, have frequently been targeted by thieves over the years.
In 1976, in one of the largest ever art robberies on French soil, 118 Picasso works were stolen from a museum in the southern French city of Avignon.
Twelve Picasso paintings, valued at the time at some $17 mil, were stolen from the Riviera villa of another of his grandchildren, Marina Picasso, in 1989. Two local restaurant owners were arrested for the crime days later, and the works were recovered in full.