Do These Old Wives Know What My Baby Is? Day 9- History of Parent's Kids

Today's old wives tale comes from His Boys Can Swim again.  I read the craziest tales on there.  If any of these sound crazy..they probably came off there! 

Ok so today's tale is based on the history of the parent's kids.  This only works if there are three kids in the family.  Surprise Surprise...that's exactly what my parents had.  So theory is you can tell the gender of the child by looking at the other children.

The first child - will have the same gender as the middle child
The middle child-will have the same gender as the last child
The last child- will have the same gender as the first child.

Ok so I am the oldest child...my sister is the middle child and my brother is the youngest child....which means...I will have a girl...my sister will have a boy and my brother will have a girl.

My sister was the first to have a child and she DID have a boy! So according to this tale..the old wives say I am having..........a girl!!!!

This brings our eight tale total to:
100% girl
0% boy

Of course my grandparents also had three kids....My mom the oldest...my aunt the middle and my uncle the youngest.  My mom had a girl first...My uncle had a girl first (which according to the tale is correct)...however my aunt had a girl...which should have been a boy....hmmmm? 

Are there three kids in your family?  Is the tale correct?