Not a problem at United. We have many Father/Son and even Daughters working here.
I could name names, but I'd rather not. However, if you would use one of the Newspaper Search Engines that cover newspapers in the US of A you'd probably see recent pix of two pilot crews related. And I can think of of one 727 crew that was all in the same family.
Showing once again it's not the aviation qualifications that count, it's who you blow.....
Clearly, I never knew the right people....