A man (II-6) with MELAS syndrome wants to marry a woman (II-7) who is not affected with this syndrome. They (II-6 and II-7) visit a genetic counsellor because the syndrome has impacted all of the children of one of his (II-6) married sisters, and the woman (II-7) is concerned that if they marry, their children may be affected as well. An intern working under the genetic counselor whom they visited made four observations after analysing the pedigree given below. Identify which observation of the intern is not correct.