Children only have memories when they are 23 years old, and now everything is a cloud.
If your mother-in-law is a person who can work, don't care if others don't make people or keep their mouths shut. If most of the work is finished, people will keep complaining. If I were you, you would also complain.
If your mother-in-law is a diligent and clean person, she doesn't often make her sick when taking care of her baby, for example, covering her too tightly, such as not letting her drink water and eat, etc., it always appears repeatedly, even if her son doesn't correct it dozens of times, don't give it to her mother-in-law and let her go home to rest, because such people can't change it, they can only create difficulties.
If your mother-in-law is a person who can take care of children, clean and diligent, you can rest assured that she will take care of them. It's better for the baby to love grandma, and it's harder for the old, so you have no worries.