Existe algum povo não-mágico nascido de dois pais mágicos?

Houve pelo menos dois abortos nascidos de dois pais mágicos.

(Estou baseando essa resposta nos comentários da resposta do @ JasonBaker.)

• Angus Buchanan. Informações sobre o Pottermore sobre o rugby escocês revelam a existência de um Squib in a família de sangue puro Buchanan:

  By the mid-nineteenth century the Buchanan family comprised an overworked mother, a fierce father and eleven children. The household was loud and chaotic, but even so, it is surprising that neither of the Buchanan parents realised that their third son, Angus, was a Squib – a wizard-born child with no magical powers. It had always been the proud boast of Mr Buchanan senior that such an anomaly had never occurred in their family. The proud old warlock went further: a Squib in any family was a sign that they were in decline and deserved to be winnowed out.

  Particularmente notável é que Angus chegou até a Cerimônia de Seleção em Hogwarts antes de ser desdobrado como um aborto.

  (Baseado em informação de Pottermore , ele também é o único Squib a fazer isso.)

• Marius Black. Ela era um membro da notória família Black-supremacista, que foi expulsa como um Squib e prontamente explodiu fora da árvore genealógica.

  Nós vemos a porção destruída da árvore genealógica no filme Ordem da Fênix . Havia também uma árvore genealógica produzida por JK Rowling para caridade, uma cópia da qual pode ser encontrada na HP Lexion a>. Ambos os pais dela ainda estão na árvore (tão improvável que sejam Squibs); a lenda nos diz que ela era um aborto.

Existem muito poucos Squibs em canon (os outros são Arabella Figg, Argus Filch, os irmãos Thurkell e o irmão de Dolores Umbridge). Não sabemos o suficiente sobre a parentesco deles para dizer se algum deles tinha dois pais mágicos.

(Sabemos que os pais de Dolores Umbridge não eram ambos mágicos; sua entrada de Pottermore nos diz que ela tinha vergonha de seu parentesco meio-sangue e tentou esconder isso. h / t Nathan K. Campbell por me lembrar que sabemos disso.

Na medida em que "trouxa" significa "pessoa incapaz de realizar magia", então sim. Estes seriam os Squibs e J.K. O antigo site de Rowling ¹ diz (ênfase minha):

A Squib is almost the opposite of a Muggle-born wizard: he or she is a non-magical person born to at least one magical parent.

Presumivelmente, então, há abortos nascidos com dois pais mágicos; A excelente resposta do alexwlchan fornece uma lista de exemplos conhecidos.

J.K. Rowling escreveu uma pequena história sobre Pottermore sobre Angus Buchanan , que é um aborto (ou seja, "uma criança nascida por bruxos sem poderes mágicos"), nascido de dois pais mágicos e vindo de uma família mágica muito antiga.

The wizarding family of Buchanan lived in a village in the Scottish Borders for many generations. A reputation for aggression and drunkenness, coupled with their prodigious size (the daughters alone had won the village tug-of-war every year in living memory), kept their neighbours at a respectful distance and ignorant of their magical abilities. One by one, as they reached the age of eleven, the Buchanan sons and daughters would disappear to Hogwarts. The village whispered that the enormous, wild children were being removed to a corrective facility or even a mental institution.

By the mid-nineteenth century the Buchanan family comprised an overworked mother, a fierce father and eleven children. The household was loud and chaotic, but even so, it is surprising that neither of the Buchanan parents realised that their third son, Angus, was a Squib – a wizard-born child with no magical powers. It had always been the proud boast of Mr Buchanan senior that such an anomaly had never occurred in their family. The proud old warlock went further: a Squib in any family was a sign that they were in decline and deserved to be winnowed out.

De Harry Potter e a Ordem da Fênix (filme)

Marius Black was a Squib, third child of Cygnus Black II and Violetta Bulstrode, and brother of Pollux Black, Cassiopeia Black, and Dorea Black. Marius was disowned and removed from the Black family tree tapestry for being a Squib

link

Além disso - de acordo com Harry Potter Wikia (com Pottermore como fonte)

Angus Buchanan (15 January, 1847—21 February, 19271) was a Scottish Squib born to the pure-blood Buchanan family.

link

É muito provável que existam essas pessoas. Prova disso é que Neville Longbottom nasceu de dois pais de Mago, mas sua família achou que ele não era mágico quando era jovem.

De Harry Potter e a Pedra Filosofal capítulo 7.

[…] ‘but the family thought I was all Muggle for ages. […] Great-uncle Algie came round for tea and he was hanging me out of an upstairs window by the ankles when my great-auntie Enid offered him a meringue and he accidentally let go. But I bounced – all the way down the garden and into the road. They were all really pleased. Gran was crying, she was so happy. And you should have seen their faces when I got in here – they thought I might not be magic enough to come, you see. Great-uncle Algie was so pleased he bought me my toad.’

Augusta Longbottom nos conta que ambos os pais de Neville eram mágicos em Ordem da Fênix capítulo 23.

‘What's this?’ said Mrs Longbottom sharply. ‘Haven't you told your friends about your parents, Neville?’

[…]

[…] said Mrs Longbottom. ‘My son and his wife,’ she said, turning haughtily to Harry, Ron, Hermione and Ginny ‘were tortured into insanity by You-Know-Who's followers.’

[…]

‘They were Aurors, you know, and very well respected within the wizarding community,’ Mrs Longbottom went on. ‘Highly gifted, the pair of them. […]’

Neville's mother had come edging down the ward in her nightdress. She no longer had the plump, happy-looking face Harry had seen in Moody's old photograph of the original Order of the Phoenix. […]’

A fotografia foi descrita com mais detalhes no capítulo 9.

From an inner pocket of his robes Moody pulled a very tattered old wizarding photograph. ‘Original Order of the Phoenix,’ growled Moody. ‘Found it last night when I was looking for my spare Invisibility Cloak, seeing as Podomore hasn't had the manners to return my best one … thought people might like to see it.’

[…] ‘That's Frank and Alice Longbottom –’

Harry's stomach, already uncomfortable, clenched as he looked at Alice Longbottom; he knew her round, friendly face very well, even though he had never met her, because she was the image of her son, Neville.

‘– poor devils,’ growled Moody. ‘Better dead than what happened to them … […]’

Ordem do Phoenix capítulo 30 também revelou que Frank Longbottom era um auror, mas não afirmou sem ambiguidade que Alice também era um bruxo.