Yvonne married William 'Bill' Brill, a crucial figure in her life who provided support and understanding throughout her career. He was a strong advocate for her work, particularly during times when she faced gender bias in the engineering field.

Yvonne and William Brill had three children. Balancing her demanding career with raising a family presented challenges, but she managed to excel in both areas.

In her retirement, Yvonne continued to pursue her interests and remained engaged with the engineering community. She enjoyed spending time with her family and traveling.

Yvonne Brill passed away in Princeton, New Jersey, at the age of 88. Her legacy as a pioneering rocket scientist continues to inspire future generations of engineers and scientists.