First foremost, Ill tell my spouse and share with him what I think and what's my opinion in regards to ur MIL = his mum. Then, tell him to let his mum know (he has to be centre person), but if it doesn't seems okay, then, ill speak with her in the presence of FIL and spouse. But, if it is not comfortable, I will tell her directly.
Every parents have to know that each grandchildren is different, no two person are the same. Hence, whatever we do to our kids, how we upbring, what we give to them is entirely up to us. We do our way, our style.
If your MIL think that you are not doing this and that. Loudly/purposely tell her like " Arh b, I bring all the necessary, makesure double triple check if not later missing lah, forget lah, etc" This is indirectly letting your MIL know you have done your duty and checklist as a mum. Your spouse has to act and do along to ensure he support you. If you are packing things, you makesure your spouse help you too and you sound him "Ehk you pack this already right? No missing things right? Arh dont forget important things arh, later your kids cranky." 🤭😅 Must drama abit.
Pertaining food, kids nowadays can be fussy. So you must let her know as long as they eat rice, bread, cereal they are filling up their tummy with food not junk. It is not everyday kind of food. As long as they eat rather than being so picky and refused to eat. Which one she prefer eat or picky?
You, do your duty as a mum. She does her duty as a grandma. Am I wrong? Not at all. I take what's gd from my MIL/mum and if certain opinion not needed, ill ignore 😌 I am me. I am firm. Thank God, my husband knows my ugly side and my nice side 🤭