I agree with Darkestlight. There are a lot of different options. One possibility is that these are "Choroid plexus cysts" which can be part of normal fetal brain development and often disappear spontaneously before 32 weeks gestation. Other types of cysts can be markers for other conditions.
Does your daughter have a follow-up with a specialist?
When u say embryo... how many wks pregnant is the mother?
Cysts appear on fetus' all the time. Most of the time they fade. Other times they are a indicator that something else is wrong.