Family, no. Friends, yes.
I'm always curious how other same City derbies play out, but I think the Sheffield one is quite unique in that both clubs have always been pretty close. I mean we are more successful than them, have won more, spent more time in the top divisions and competing for honours, but it's not like Liverpool or Manchester where one club is so, so much more successful than the other, and where the real rivalry in terms of competitiveness is arguably with a team in another City. When the lesser successful club gets their moment on top - as a result of us being shit more than them actually achieving anything - they become insufferable about it. For a full decade.
I guess the equivalent would be if Everton and Manchester City consistently finished above Liverpool and Manchester United every single year for 10 years, or even started winning league titles and Champions Leagues having played second fiddle to their same City rivals for decades.