Does the apple fall not far from the tree in operations research? Who are well-known Parent/Child pairs in operations research? I can't claim this: my father was a chemist and my son, at fifteen, has not yet caught the OR bug.
Another father-daughter pair is Matteo Fischetti of U. of Padova and his daughter Martina Fischetti who recently completed her Ph.D. at DTU with David Pisinger.
Are we still waiting for mother-child pairs? Hopefully soon...
In Montreal we have Louis M Rousseau whose father Jean Marc Rousseau was also a professor until he quit academua to start his own company (GIRO).
From Chile there is Gabriel Weintraub, professor at Stanford and the son of Andres Weintraub.
From Brazil, there's Daniel Aloise, professor at PolyMtl, the son of Dario Aloise from Natal RN.
For sure there is Bob Bixby and Ann Bixby. Ann did her Ph.D. at Northwestern with Collette Coullard. Also, a bit of a stretch, since his father was more of a mathematician, but there is also Gunnar Carlsson (Stanford Math) and Jon Carlsson, who is currently at USC.
John D.C. Little, of $L = \lambda W$ fame : father
John N. "Jack" Little https://en.wikipedia.org/wiki/John_N._Little and https://www.mathworks.com/company/aboutus/founders/jacklittle.html, President and co-founder of The Mathworks (MATLAB): son
Jack received degrees (S.B. from M.I.T.) in Electrical Engineering. Given that when I was accepted into the M.I.T. O.R. Ph.D. program, I was assigned to the Electrical Engineering (course 6) department, and in light of Jack's role in the development of MATLAB, which is heavily used in O.R., being second only to Cleve Moler, I think we can consider Jack to be close enough to O.R. for government work.
There are Robert Tibshirani, the father of the LASSO, and his son Ryan Tibshirani. Even though they mainly work in statistics they also have made some valuable contributions to the OR-community such as the LASSO, several contributions in Machine Learning or this comparison of regression methods.
Only few of you may know Erik Demaine who is not only a computer science prodigy and artist, but so is his father, Martin. They publish together.
Raffaele Cerulli from U. Salerno and his daughter Martina Cerulli — PhD student in Paris with Leo Liberti and Claudia D’Ambrosio.
I learned of another one recently. Again depending on how broad your definition of "OR" is. There is Jim Orlin from MIT and his son Ben Orlin, of Math With Bad Drawings fame. (https://mathwithbaddrawings.com/)
François Louveaux (mostly known for the book on stochastic programming he coauthored with John Birge) and Quentin Louveaux, both of them in Belgium (UNamur and ULiège, respectively).