Why is my mom so embarring?

GRRRRRR! yesterday we went to some friends house and she was talking about her life with her friends and sometimes shes so stubborn and she starts talking about me to her friends about how i develop. sometimes she says: marina (me) is developing slowly. she just has really small . im happy she doesnt have big ones like me" and i went outside to have some cake and then she started embarrasing me and talking about my friend developing because my friend was wearing a type of shirt with the s space and shes like "hey r u getting ? marina is starting to get bigger ones too" and im like "ughh mom!!!" and my moms like "what, its normal, dont be embarred." and my friend's like "ok? hahaha" and then my moms like "what? its cool and nice to just have them there you look 'y' " and then my friend is like "ahaa ok yeah whatever" and then my mom kept continuing on developing and bras and shes like "what? when you grow your you can have some of marina's old bra"