Free ear lobes is the dominant allele with attached ear lobes being the recessive allele. If the woman is homozygous dominant, meaning both of her alleles are for free lobes all children will have free lobes because the dominant allele always wins out.
If the woman is heterozygous for free lobes meaning she has one allele for free ear lobes and one allele for recessive ear lobes, half of the children could have free lobes, while half could have attached ear lobes.
In the second example I used the word could because each child would have a 50% chance of getting each allele. It could be that all children would have free or all children could have attached, it just depends on which allele each child receives.