Answer
Yes, with the chance being 50%.
Work Step by Step
Use G=glaucoma allele, and g=non-glaucoma allele. Each of the females in the third generation is descended from one affected (Gg or GG) and one unaffected (gg) individual. Given that the trait (glaucoma) is dominant, this means that each of the third-generation females must have one allele for glaucoma and one (recessive) non-glaucoma allele (Gg). The unaffected male whom she will marry must be homozygous recessive (gg) since even one of the allele for glaucoma would lead to glaucoma. Thus, the unaffected male will provide the no-glaucoma allele to all offspring, and the third generation female will provide a glaucoma allele (G) 50% of the time and a non-glaucoma (g) allele 50% of the time, which will also be the frequencies for glaucoma and non-glaucoma cases among her children.
