Doctors in Germany say quadruplets born prematurely three months ago to a 65-year-old woman are doing well and can leave a Berlin hospital soon.

Charite hospital said Tuesday that the babies all weigh more than 2.5 kilograms (88 ounces) and should be able to go home this month. The quadruplets are a girl named Neeta and three boys named Dries, Bence and Fjonn, who were delivered during the 26th week of pregnancy by cesarean section on May 19.

Mother Annegret Raunigk is believed to be the oldest woman to have ever delivered quadruplets.

The retired schoolteacher already has 13 other children aged 10 to 44 from five fathers. She traveled abroad to have donated, fertilized eggs implanted, a procedure that's illegal in Germany.