Missing a day

@Celinio14 A couple of things you could try...

• Reset the pregnant Sim
  
  Spoiler

  Method 1 (works Sim or object)
  
  Enable Testing Cheats:
  • With your lot open, press Shift+Control+C to open the cheat console box (upper left of your screen). Enter the following in the cheat code box…
  testingcheats on (press enter)
  (Note: testingcheats true also works)
  • You will see a confirmation message: “Cheats are enabled”.
  
  Reset/debug:
  • ‘Shift + click’ on the Sim or object and choose “Reset Object (Debug)” from the pie menu that pops up.
  
  Method 2 (works only on Sim)
  
  2-Steps: With your lot open, press Shift+Control+C to open the cheat console box (upper left of your screen). Enter the following in the cheat code box…
  Enter the following in the cheat code box…
  resetsim <First name> <Last name>(press enter)
  
  
  Options involving leaving the lot:
  Many times if a Sim or object is not functioning properly, freezes, or your household/lot becomes unresponsive, you can:
  • Leave the lot and go to the “Manage Worlds” (world map). The game may or may not allow your to save when you exit the lot, depending on what is not responding. Then return to the lot. See if the game &/or object/Sim is now behaving normally.
  • Leave the lot and choose “Exit to Main Menu”. The game may or may not allow your to save when you exit the lot, depending on what is not responding. Then return to the lot. See if the game&/or object/Sim is now behaving normally.
  • Leave the lot by choosing to “Exit Game”. The game may or may not allow your to save when you exit the lot, depending on what is not responding. Then restart your game and return to the lot. See if the game &/or object/Sim is now behaving normally.
  • Try traveling with your Sim then return to the lot. See if the game &/or object/Sim is now behaving normally.
• Roll back your game to a save, if you have one, before the birth.
  
  Spoiler

  To return to a previous save:
  
  In-Game Method:
  Go to the Main Menu and choose 'Load Game'. Select a saved game, then hover over the small folder icon and click this icon.
  This will reveal your most recent saves on that 'Game Save'. Select the 'Recover' button on the version (see time stamp) that you prefer.
  
  Game Files Method:
  Or you can do this in the game files by following the directions here:
  https://help.ea.com/en-us/help/the-sims/the-sims-4/how-to-restore-a-previous-saved-game-in-the-sims-4/

Another thing to note for in the future is that you will be able to change the baby's name in CAS once it ages up to toddler. 

Thanks, tried resetting, that didn't work my Sim went to the hospital for the second time because she was in labour but no baby was born and through CAS i made the baby they had the first time their daughter again, as she was just there as a member of household. 

@Celinio14 That's good news that it fixed her family tree then! I'm happy to hear it worked out, after a fashion. Thanks for the update! 🙌