STICK to your stance. No, you are NOT over-reacting. Your Hubby NEEDS to be in agreement with you. He has to stand up to his Mom. Your MIL is not careful for one, not safe, not a good "supervisor" of kids... this is not good.
Just tell her that you/Hubby already made plans for your daughter.
Second, you girl has never been over-night, at anyone's home... PLUS she will be in a DIFFERENT locale, PLUS... she is only 1 year's old, PLUS, she will be away from her Daddy for 2 days at least. This will be a BIG deal to a little girl.
THIRD, there IS a choice here... it's not like you HAVE TO leave her at your MIL's house....or for an emergency that can't be avoided. You CAN avoid this.
FOURTH, is your MIL's house "child proofed?" It does not seem to be. A 1 year old child is very active, can choke, fall etc. Once, while my friend's Mother was baby-sitting her toddler son... he had "escaped" out the back door... and her Mom did NOT even know.. .her son was found outside in the driveway. When my friend asked her Mom about it, all her Mom said was "oh, I thought he was in the living room...." OOPS!
Mind you, this was at home when it happened... Grandma "lost" her boy, at home! Imagine now... if they were out in a public place... and her boy was lost because Grandma lost sight of him or could not keep up with him???? What then? My friend learned from this.. and now is very skeptical if having her Mom babysit. AND, what if your MIL takes your daughter out... in the car??? What then? Is your MIL a safe and good driver???
Think about all these things... I would.
FIFTH... your MIL has a habit of leaving medications and medical supplies laying around. OOPS! You must never overlook these "lapses" of judgment.
YOU are the Mom, and your Hubby NEEDS to see clearly on this... instead of everyone giving in to MIL. A Child's BEST interest should be FIRST and foremost. Not, pleasing a "careless" Grandma.
What does your Hubby say about all this? His daughter should come first... and her well being, and his Parenting.
Plus, you MIL will NOT "know" your daughter well enough to know her routine, her personality, her "needs" either.
Me... I would not agree to this. My child would come first... and Daddy has to be on the same page.
You are the Mom... and Grandma does not know enough to handle the situation. She does not seem to know enough about how to handle the safety and emotional well being of a young child. PLUS, you will NOT be there to run interference.
A well meaning Grandma who does have other endearing qualities is one thing... BUT, leaving a child there, without her Parents in the care of a careless Grandma... is a mistake. REMEMBER... IT JUST TAKES A SPLIT SECOND FOR AN ACCIDENT TO HAPPEN... then what??? Does your MIL know CPR? Are her reactions and reflexes "quick?" Is her thinking Clear and cognizant in case there IS an accident???? Think about that....
I agree with you. Make sure Hubby is aware of all these aspects... not just the "emotional" obligation to his Mom or the guilt trip of "offending" her.
If anything... SHOW YOUR HUBBY THIS AND ALL THE RESPONSES YOU GET.
Good luck,
Susan