parenting opinions from others

how do you cope with family, in laws, friends, even strangers telling you how to parent? for example, my MIL keeps telling me to give our 17 week old baby solids, because she did with her kids at 8 weeks old and they were alright, slept better etc, and our baby needs it. I've explained the guidelines are not until 6 months and why that is but she just rolls her eyes. my mom is quite insistant on it too. what 'advice' did you get and how did you respond?