Glad to hear children can still be heirs @miwa09 since, after your previous message, I haven't test played it myself yet (am still planning too though). Thanks for letting me know.
About the "Save"/"Save as" problem: I never use the "Save" option but always "Save as" and work with several saves throughout each Kingdom. I always "Save as" with the name of the Kingdom and profession of the hero I am currently playing so every hero has his or her own save per Kingdom, I have a "Save as" with the name of the Kingdom and the word Kingdom behind it which I use in between quests when placing buildings and decorating and stuff and often I use a "Save as" which I call as the name of the Kingdom with the word temporary behind. This save I use before choosing a legendary trait or when I want to see how a certain choice works out. In case I don't like it or change my mind, I restore that temporary save. When I'm finished with my Kingdom, and had the "you have platinum/gold/whatever message", I use "Save as" once more to save under the name of the Kingdom or the name of the Kingdom and Ambition. Those saves I keep in my Documents since I use those saves to have all my Ambitions unlocked, you know what I wrote about earlier. The temporary and heroes saves I throw out when I'm done with a Kingdom. So for me it's the same as sam123 and I haven't had that issue. It's always a good precaution to make regular backups of your saves, for example every time you're done playing for the day since saving in every Sims game is unfortunately and still never without risks.