There wasnt any confusion like you suggest. its like when somebdy wakes from a coma that is all they will usually remember not what happens while they are in a coma. she was still lost in time from being sealed once awakened she awakened in her old state and made an assumption then realised it wasnt the 2.
Perhaps i missed something but if i woke from a coma and saw two people id assume it was the last people i saw(those that sealed her) until i catch up with my self. Once i realise its not them i come to the correct conclusion they are the descendants of rokudo sennin. not his brother and the sage confirmed this. Unless your suggesting the sages wife was boned by homura and he asumed ashura was his son. And what is too say she mistook ashura for hamura and not sasuke. Itd make more sense since the byakugan is the ancestral eye of the sharingan.
Have you read todays chapter she saw hogaromo when nardo used his power and he had the same marks. so it ads weight to what i said.