Have any of y'alls kiddos suddenly stopped taking naps during the day? And/or sleeping through the night?

My little 4 month old used to take great naps during the day and sleep at least 8-9 hours a night without waking up, but all of the sudden she fights naps so hard and IF she takes a nap it's like 20 minutes long.

What are some things that I can do to try to get her to sleep again? Or do I just need to wait it out?

Please, please help!! Thank you so much! 😊