Then tell her mother-in-law clearly that things at home should not be handled casually. My husband and I have plans, such as my son's little clothes, which are for colleagues. The things in the refrigerator don't need to be cooked, so they are stored in our house across the hall.
But remember, don't start a conflict from your side. Tell your husband as soon as you get in touch with your mother-in-law, so as not to convey it from her mother-in-law to her husband in another version.