>One common misconception surrounding Mitochondrial Eve is that since all women alive today descended in a direct unbroken female line from her, she must have been the only woman alive at the time.[45] However, nuclear DNA studies indicate that the effective population size of the ancient human never dropped below tens of thousands.[49] Other women living during Eve's time may have descendants alive today but not in a direct female line.[50]

https://en.wikipedia.org/wiki/Population_bottleneck#Humans