Lowering down to chaturanga is quite difficult when you are just beginning your yoga journey. It involves building strength in your chest, which for most women, is an area that we are lacking in strength.
In between classes, I encourage you to roll out your mat at home and grab two blocks; place those blocks shoulder-width apart, with your hands on the blocks, and be sure that your thumbs are in line with your chest. Have your knees on the ground and focus solely on building strength in the chest. Remember, core needs to be pulled in and engaged. Take a deep breath in, slowly lower down, and hover on the exhale.
See how my bum is lifted slightly in the picture so that my spine is long? Make sure that you aren’t sagging in the lower back. To correct that draw the belly in and feel the lift through the back. Then push yourself back up to straight arms. Try several rounds every day to build the strength you need to safely and properly do chaturanga.