If your mom can and wants to stay and your hu*****and has no objection, let her stay till the baby 2 or 3 years old and then put her to daycare. Talk to your hu*****and gently and firmly about it. I think your worry about your baby and your mother-in-law getting too close to her and brainwashing her.
Let your hu*****and take the baby to visit his mom , and you take your mom out and spend some time with her.
Don't say bad words about your mother in law and be a good wife to your hu*****and so your hu*****and can defend you in front of his mother like what you illustrated in one of the posts.
Sweet talk to your hu*****and and try to take care your small family to build strong bond. Let your hu*****and deal with your mother-in-law. But you hold on tight your own money. Drop the issue of 10K money unless you want divorce.