Question??? Glass Bottle or plastic for new born!

McKenzie • Married👰 Office Administrator🖥️Mother to a bussy 2 year old boy👦 and pregnant with my baby girl👶.💗💗💗

Hi ladies

My mother in law recently told me she did not want me using a plastic bottle for the first couple of months?!

Ive never heard of this and why is she so pushy about me using a glass bottle???