I've had this happen to 2 different heirs in the same family. The first was a unpleasant surprise and she had just gotten married but I went along with it because it took my game into a different direction which can be refreshing.
The 2nd time I was not happy. My heir had just had her 3rd daughter and i sent her to go eat. Hubby and the oldest were at school, while the toddler and newborn were both sleeping. The next thing you know I'm looking at the kitchen table but Iylah is not there...then time speeds up and I saw grimmy. Needless to say I quit without saving. Didn't want Sheldon being widower with 3 small children.