Hilda's mother was also a mathematician who had read mathematics at Newnham College, Cambridge, so perhaps it was not entirely surprising that William and his wife should have had children with outstanding mathematical talents who went on to study mathematics at Cambridge. Hilda had an older brother, R W H T Hudson, who was Senior Wrangler in the Mathematical Tripos at Cambridge in 1898 while her sister was bracketed with the 8th Wrangler in the Mathematical Tripos of 1900.
Hilda ng ina ay din ng isang dalub-agbilang na basahin ang matematika at Newnham College, Cambridge, kaya marahil ito ay hindi ganap na kagulat-gulat na William at kanyang asawa ay dapat ay nagkaroon na bata na may natitirang matematiko talento na napunta sa pag-aaral sa matematika sa Cambridge. Hilda nagkaroon ng isang mas lumang mga kapatid na lalaki, RWHT Hudson, na siyang Senior Wrangler sa matematika Tripos sa Cambridge sa 1898 habang ang kanyang mga kapatid na babae ay bracketed sa ika-8 ng Wrangler sa matematika Tripos ng 1900.