Im really getting sick of my boyfriends sister. I get that shes only 17 and she doesnt quite know how everything works…

Im really getting sick of my boyfriends sister. I get that shes only 17 and she doesnt quite know how everything works but to question every little fucking thing i do with my daughter and questioning everything my doctor says gets really annoying. this is my baby, my second baby actually. i know what im doing.