Gabby hasn't learned how to sit up on her own but when we put her in a sitting position, she can sit quite steadily already. She's even learnt how to use her hands as support when she's losing balance. But there are times when she would stretch over to her sides for her toys and lose her balance. It's very cute to see her slowly leaning to the side and land on the floor.... haha... Don't worry.. she won't hurt herself as the mat's thick enough to cushion her.