Countess Maud Herbert De Percy (Herbert / Huber) - British Royal family, & Blackforest

Anne Margaretha Faller (born Huber)
born1480
Oberfallengrundhof 1, Furtwangen, Freiburg, Baden-Württemberg,
and her parents: Sir Henry Thomas De Percy, 4th Earl Of Northumberland
1449 - 1489
& Maud Herbert Countess De Percy, 4th Earl Of Northumberland (born Herbert; Northumberland)
How - Why did this British Royal family have a child born in the Black Forest??? Has Any one explored this question?