Writing a letter to my swimming teacher - how to address her?

Question

I'm writing a letter to my swimming teacher asking her if I can help out in her life-saving class next term while I wait until I'm 16 so I can become a lifeguard, but I'm not sure how to address her.

Her name is Wendy Davies. I get on quite well with her, and 'Mrs Davies' seems too formal but I'm not sure.

Should I write:

Dear Wendy,

Dear Wendy Davies,

Dear Mrs Davies

Or something else?

Then how shall I sign off at the end: yours sincerely?

Weird question I know, but it makes all the difference!

Answer 1

Dear Swimbo

Dear Fishy Friend

Dear Hamburger Queen

Dear Diving Davies

Answer 2

Dear Mrs Davies,

Sincerely yours,

Answer 3

The rule of thumb I follow is with a teacher or boss or someone in a position of authority, err on the side of caution and call that person Mr. or Mrs. (or Ms.!) until that person has specifically said it was okay to call them something else.

I would address the letter to Mrs. Davies unless when you talk to her you call her Wendy.  And I would close the letter with Sincerely or Best regards.  

Hope this helps!