Ms is a proper way to address a woman when unaware of her marital status.
When addressing an envelope to a recent widow, it is customary to write the person's name starting with the title "Mrs.". Just because a woman is a widow does not mean that a woman is not still married.
If you are addressing a married woman use senora. If it is a child or an unmarried woman use senorita.
I was always told that you never seperate a man's name. So, if you are addressing a card or envelope informally, and the couple is married, it should be addressed: Jane and John Doe
A respectful way of addressing a woman is to call her Ms. or Miss. This is polite even when you do not know if she is married.
Addressing an envelop to a woman with a boyfriend and young son: Just address the envelope to: Ms. Jane Doe & Mr. John Doe (if the young son is in their teens, but not necessary if they are a minor) & Mr. John Smith. So the envelope may read: Ms. Jane Doe & Mr. John Smith.
Mrs. is when a women is married. Ms. is when they are not married. Miss is when thay are younger.
If you do not know if the woman is single; married or widowed then you can use 'Ms.' If you know they are single then use 'Miss' or 'Ms.' and 'Mrs.' for married women or widowed women.
ethnicity has nothing to do with it.
When addressing a woman, you can use the title Ms. or Mrs. based on her preference.
"Mrs" means the woman is (or has been) married. Ms" means either of the above but the woman prefers not to reveal which, or is used if you are addressing her in writing and don't know whether she is a "Mrs" or a "Miss".
Mrs means that the woman is married hence her last name is her married name. Miss means that the woman is not married and the last name is her maiden name. Ms could mean that the woman is divorced but has kept the married last name, or that the woman is married and has kept her maiden name???? maybe??? not too sure on Ms
What's wrong with it? As long as nothing between them is happening, friendship is nothing to be ashamed of.