Name that Title

I've been trying for a long time now to remember a title of a book I read in grade school. I'd love to read it now (I tend to read my old kiddie books as a stress reliever sometimes, but this is one title I got from the school library.)

It's a book about a girl who goes to boarding school (might be England, but I'm not sure) and she and her friend dressed up as ice cream cones for Halloween (don't know why I'm thinking mint chocolate chip, they probably didn't even mention the flavor, and my memory is just that bad). That's about all I can remember. And I asked my childhood friend who read the book right before I did, and she had no idea what I was talking about.

So at the risk of sounding like a complete lunatic, if this title sounds familiar to anyone, could you let me know? (I read this book in the mid to late 80s, if that helps).

Thanks sooo much! That title doesn't jog my memory, but I think I'll read it anyway to find out if it's the right book. The boarding school and age-range of the girls seems right (based on the Amazon description), but the time period (early 1900s) just doesn't trigger my memory entirely.
thanks for the suggestion. i still might have some more detective work to do, but it looks like a fun read. And I knew someone here would point me in the right direction (and not think I'm too weird

ok, this is too funny I just googled "ice cream cones boarding school" not really expecting anything, and this was my first result
http://www.whatsthatbook.com/index.php?xq=1534

i'm pretty sure that's the title because the person who wrote it mentioned pistachio ice cream cones, yes, i knew it was something green.

that was my most successful google search ever.

and thanks again Silver King I should probably devise a list of boarding school titles and read them all! I always loved the Facts of Life.