Your mother-in-law is "only saying":
• "He looks a little skinny."
• "My babies were eating link sausages and goulash by this age."
• "I ironed the crib sheets, but you do what you like."
• "There's always time for polishing the silver."
• "Try a little sugar in her bottle." "Try a little whiskey in her bottle." "Try a little dill water in her bottle."
• "A little lipstick never killed a person."
• "What? I'm only saying ..."