I had the same problem when I was three. I didn't know how to cross my legs so whenever I sat I just had my butt on the ground and my legs sticking out straight

I had the same problem when I was three. I didn't know how to cross my legs so whenever I sat I just had my butt on the ground and my legs sticking out straight in front of me. When the teacher said I had to cross my legs i just crossed them via putting one ankle on top of the other. I did this for about two weeks before the teacher finally grabbed my legs and shoved them into the cross legged position . From then on I learned how to cross my legs.