DD has great heat control and has for a while. But when I put her on her tummy she screams and seems out of breath. She does try to lift up her head but for the most part just mashes it in the mat. When I have her sitting on my knee or on my shoulder she does great. I am getting worried because she is not trying at all and had not idea what to do with her arms and the more I put her on her tummy, the more she cries. Any suggestions? TIA.