I can understand your feeling
Sometimes, mother in law are too excited to offer advices to daughter in law because they feel they have more life experiences but they fail to realise that sometimes what is OK in the past is probably NOT OK now.
As for me, i will appreciate the advices but please do not force the opinions on me. Allow me to choose what i want for my kids, and allow me to learn from mistakes. They have got their chance and this is our chance as a mother.
I also sent my baby to my mother in law last time, but she was trying to impose her idea of what she wants for my baby, and somehow have crossed the boundary and disrespect me as the mother..When i rejected her advices, she sneakily did things behind my back when i was at work or secretly persuade my hubby (who is a mummy's boy) to do what she wants.I eventually realised that sending my baby to her care is a BIG mistake, as she becomes more and more possessive of my baby day by day and it has caused me to hate her and creating this gap between me and her.
So, i decided to send my baby to the nursery instead (better, because it is nearer to my place). But she even went as far as discussing with my husband's relative and talked to my mom about what a big mistake i have made sending baby to the nursery when i should have trusted her as she have brought up 5 successful kids before. But i persevere and persistent with my decision. In the end, she gave up and now i feel more at peace.
my advice is if she is offering you advice take it with a smile and nod as in you respect her (old people like people listening to them), but if you dont like it just dont't do it. If she goes as far as being pushy and try many things to make you do what she wants , just told her directly that you would prefer to do your way and give your reason. You must stand firm on your feet, be tough but polite, you must let she knows what you think otherwise she will keep pissing you off... stop going to your husband because trust me it wont resolve your problem infact it makes things worst because your mother in law will start thinking that you trying to make her son goes against her....(same thing if she talks to your hubby behind your back.. will you like it??)