Mrs N

I took over my ensemble this year as the former conductor was on maternity leave.  I'm of average height, dark brown hair, and not pregnant (fairly fit, in fact).  The other teacher (Mrs N) is about the same height, light blonde hair, and was rather pregnant when she left to have her baby.  Occasionally, a child would slip up and call me Mrs N instead of Miss M.  One child just couldn't get her brain to change though.

Girl [distracted]: Mrs N...?
Me:.... Ummm....
Girl [suddenly coming to]: Oh!  Mrs... Mrs... Miss... Miss M?!
Me [smiling]: Yes, J?
Girl: I'm so sorry.  I just... I keep calling you Mrs N!
Me: Yeah, I noticed.  But that's okay.  I'll just start calling you... Annabelle... every time you call me Mrs N.  There are enough of them in this group.
Girl [giggling]: Okay... So, Mrs N...
Me [I can't believe this happened right away!]: Yes, Annabelle? [All the actual Annabelles congregate upon hearing their name]
Girl: Oh no!  I did it again!  I mean, Miss M...?
Me: Yes, J?
Girl [looking down]: Oh... Wait.  I can't remember what I was going to say...
Annabelles: Which one of us do you want?  What do you need?
Me: Oh, nothing.  It's just when someone calls me Mrs N I'll call them Annabelle. 
Annabelles: Even F? [the only boy in the group]
Me: Yes, even F.

Cue riotous giggles.