Several people have asked that question, and several people have decided the remaining parent's fate according to what they wish. (Some have decided that the parent has simply moved to a vacation spot of their choosing!) In the game, however, the remaining parent is removed, although, as you have noted, they can still be alive. This is normal.

She's moved to Florida.

Hehehe She pretty well could have :)Not sure if she had some pension from her job that let her though, she didn't make much. :P Which reminds me; is it just me or in the lite version, each generation after, their salaries seem to keep getting lower and lower? :P