An reasonable enough read, but I am going to destroy a basic assumption in its structure.
The father is Scottish and impliedly born in Scotland. This means that the daughter born in the US has UK citizenship directly. Even if he was born in the US she is still eligible. The eligibility goes parent is British and born in UK then child born in America can claim UK citizenship but it stops there, next generation not eligible. My case I was born in the UK, my son in Australia, he has a UK passport but his children won't be eligible..
More, with Prince Harry and the witch, Archie born in the UK and has UK citizenship and passes it down to his children and then it stops. Lillibet born in the US has UK citizenship but her children won't have it.