Devahuti was too sexually excited, and therefore she discharged more ova, and nine daughters were born. It is said in the smrti-sastra as well as in the Ayurveda that when the discharge of the male is greater, male children are begotten, but when the discharge of the female is greater, female children are begotten. It appears from the circumstances that Devahuti was more sexually excited, and therefore she had nine daughters at once. All the daughters, however, were very beautiful, and their bodies were nicely formed; each resembled a lotus flower and was fragrant like a lotus.
Source: A.C. Bhaktivedanta Swami Prabhupada (2014 edition), “Srimad Bhagavatam”, Third Canto, Chapter 23 – Text 48