LW's son and daughter in law sound awesome: spending their time on things they enjoy and making the most of their lives. I also feel really strongly that people who don't want children shouldn't have them and definitely shouldn't be nagged to have them or told they'll "change their minds". I wanted and planned to have both my children, and for all the joy I have in them, it's been a heck of a life-changing experience and commitment.

(You are also an awesome person, and I fart in the general direction of anyone who tries to make you feel otherwise.)