I'm new to ERFYT and wondered if anyone could tell me which chapter of the book addresses Grandma's revenge?
I am a B; my mother was an O and father was an A

Thanks for any help,

Suzie    

I think pages 337-338 are relevant although they do not mention Grandma's revenge by name.

Incidentally Grandma's revenege will cover
two type A parents having an O child.

It also covers two type B parents
Having an O child.

Grandma's revenge would not allow an O and an A parent to have a B child.

Quoted from 7111

I am a B; my mother was an O and father was an A  

Are you sure? maybe he is an AB. Are you sure about your blood type?

An A and a B mating can also produce an O offspring as well. As will the other possibilities that C#  mentioned.

Quoted from 7111

I am a B; my mother was an O and father was an A

This would be considered a sufficient level of proof in a court of law.  These three facts cannot logically tell the whole story.  

What is Grandma's revenge?

Suzie,
your mom will have to promise to tell the whole truth and nothing but the truth!

Quoted from Sharon

What is Grandma's revenge?

Hmmm wondering the same thing myself..

inheriting certain traits from the grand parents....

Ta Lola

Quoted from Lola

inheriting certain traits from the grand parents....

I've heard the expression that some things skip a generation (twins, nervous breakdowns, hair color, etc.)  This must be Grandma's Revenge! !

well I have exerienced grandma´s revenge;
I am B and my ex boyfriend A and we had a O type daugther  
Both grandmas are O type
But really it could have been the grandpa´s as well   just not in our case cause my dad was AB and J ´s dad was A

Quoted from Henriette Bsec

But really it could have been the grandpa´s as well  

Putting this with the twins comment from above makes me think that that might be why it's called "Grandma's Revenge" as opposed to Grandpa's -- having twins is a distinctly feminine trait (men can't get pregnant). Of course, it could have something along the same lines as "mother-in-law jokes." -- Who has "father-in-law jokes"? It's only MILs! Something about female-ness, I guess.

... there are always somebody who can testify the identity of the mother, but nobody about the father, so ...  

Henrietta I found this:

Parent 1 Blood Type     Parent 2 Blood Type
B                   A
Possible Type of Child

A, B, AB, O
_____________________________________________

Also found:
parent 1 blood type  Parent 2 blood type
O                   A
Possible Type of Child
O,A,

My greenish eyes are Grandpa’s revenge.  My mom had brown eyes & my Dad blue eyes.  Some of my Mom’s siblings had hazel eyes (I think).  Pictures of her parents looks like she took after her mother.  It looks like my grandfather had the light hair & eyes.  

My son also gets his eyes from his father & mine, they are blue.  So his is Grandpa’s revenge also.

Well, I'm sure about all the blood types in our equation. My grandmother was a B, so I guess I got her type.
I'm also the only child of 5 with auburn color hair and blue eyes and the only girl, so I always wondered if I was adopted, but I'm not- - and my Dad was really my Dad.
My father had black hair, hazel eyes, my Mother was a blond with hazel eyes - - but my grandmother had auburn hair and blue eyes.

Thanks for all the input out there

I am quite sure your dad was AB and not A he must have been mistyped
- my dad was !!( in the army they put him as B type- and that makes sense)
But after he got sick he was Bt several times and we found out that he was really and AB.

Quoted from Henriette Bsec

I am quite sure your dad was AB and not A he must have been mistyped
- my dad was !!( in the army they put him as B type- and that makes sense)
But after he got sick he was Bt several times and we found out that he was really and AB.

Yeah, I was going to say!  Apparently lots of ABs have been mistyped, so don't panic.