Oh me oh my - welcome to my world. It drove me CRAZY! To the point where I didn't want to visit with them.
Here is the deal - each and every time you say NO to your mother in law doing it her way - you are telling her loud and clear "Your way is wrong, you raised your child wrong, you don't know what you are doing." AND you are probably right. We've come a long way from giving children rum for a soar tooth, honey for a cough...lots of things HAVE changed, but our elders don't see it that way, they just see it as you vs. them in the child rearing department.
You need to repress your anger, vent else where otherwise your relationship could splinter with your in laws and with your husband who now has to defend both of you. NOT a fun place to be for a man. You may be right, but that is ALL you are going to be, with a grumpy in law and a grumpy husband.
Keep saying no, politely, explain again about teeth, digestive stuff and all. Remain polite when she rolls her eyes at you. Then throw her a good line.
I know things have changed with raising babies and in life and thank goodness because now I have a dish washer and a washing machine and amazing baby gagets - woooooh, I don't know how you used to do it. Hand washing cloth diapers - YUCK! We've got it made these days with our baby gear and clean ways. Not to mention tons of useful, educational material on the internet. Can you believe that less then 30 years ago there weren't car seats for babies, oh my goodness. And so many babies died from giving them honey.
And and and and and - you list could go on for years. Life has changed and we need to change with it. BUT, don't let that cause you to have a strained relationship. Your baby will grow, but if you let this fester your relationship with your in-law will not. Keep it nice, keep it clean, try NOT to get personal.
Positively glad there has been change - I wouldn't be alive without it.
M.
Little about me:SAHM to a wonderful 6 year old, married to her daddy for 16 years. Had open heart surgery 3 years ago. MY IN LAWS WHERE THE ONLY ONES TO HELP DURING MY SURGERY.