I'm probably being v unreasonable but here goes.
i have a freind who has recently adopted a very small baby at 8 hours old and another that has just had a baby very bad birth and is having trouble with feeding.
the one with feeding issues was told by the adopted babies mum that her milk should be here by now, and her baby is crying cause she is hungry, and to switch to formula as this is better and her little adopted angel sleeps well etc cause she has a good meal not just colostrum etc.
she also said that co sleeping will kill your child 
i really want to tell my freind who has adopted to not give advice without any experience as she cannot breast feed due to her baby being adopted.
AIBU for wanting to tell her to be quiet get educated and back off