The dr made me laugh

So my daughter just turned 4 months old so we go to her apointment she's healthy weighs well then we get into the speach of solid food she's my first so I'm kinda lost on some stuff but my parents and my boyfriends parents kept saying give her cereal I did a couple weeks early than I was supposed to but my dr says that's wrong only fruits and veggies that people in their 40s believe  it's okay but actually it leads to obesse children gluten problems and just a long list of stuff so I feel a little bad for starting her early but hell she seems fine she weighs well I don't see the issue at least not now but damn the whole thing put my mom in a tizzy an it got worse when the dr said that a birthmark on my child could actually be a third nipple an as she grows  we will know more than its my daughter will get teeth at 6 months old haha wrong she's got two now so again my dr made me laugh I mean does everything cause obesity does staring at good food cause obesity what do I know I'm just a 20 year old mother with her first child