I will make this as short as possible: My Catholic mother-in-law wants all of her daughters-in-law to call her “Mother Mary.” I cannot do this, I do not feel it is right. Can anyone give me some straightforward reasons through the Catholic Church’s teachings that could help me more logically explain this to her? She doesn’t feel anything is wrong with this; however in my heart I feel this is not something I can do. She is really causing a big problem over this. Anyone who can help, please answer.
Assuming that your mother-in-law’s first name is Mary, what is the problem? It sounds a bit convent-schoolish, but there is nothing wrong with the title for a mother-in-law.
When adult children marry, it is customary that the parents indicate to their new children-in-law how they wish to be addressed. Some prefer “Mom and Dad,” some prefer first names, some prefer “Mr. and Mrs. Anderson.” Because the parents are the elders and the children-in-law owe them the respect they give to their own parents, children-in-law set aside whatever discomfort they feel over the choice out of respect for their in-laws. When your own children marry, you can dictate to your children-in-law how you want to be addressed.
Now, if your mother-in-law’s first name is not Mary, I can see that there may be some concern about addressing your mother-in-law “Mother Mary” because there is not just cause to do so. In that case, I recommend offering to call your mother-in-law “Mother” with her surname (e.g., “Mother Anderson”).