Thank you for sharing your story to let me know that I am not alone..I faced the same situation as you, regardless whether it's about he sleeping or playing or breastfeeding episodes you mentioned but I had her help during maternity for 3 months and I stopped earlier by 1 month than planned as I really regretted it as my husband refused to step in and help after I had explained to my mil almost 5-6 times during daytime. he even threatened a divorce as he feels his mom is doing the best for the baby even for the breastfeeding portion.. Despite so, I really really appreciated her help.
Things I learnt from this episode is: tell mil that I really really wanted to fulfil my duties as a mother, if she doesn't get it, tell my husband to help to explain as they will know their mom's character to best, if he doesn't help, tell my mil firmly what I needed as a mom (to breastfeed, to play with him, and perform other motherly duties for the child). the key word is being firm about what we wish to do for/with our children because we as moms will want best for our children.