My mother, grandmother and Aunt all had the same type of Bipolar that I do. It is very strong in our family history. My 17yr old suffers with depression and agitation so I'm watching her closely. I want to make sure she just isn't going through some of the normal teenage behaviors but I think she might have bipolar. I'm just observing her for now, it's very mild.
I have read in a couple of places that the chance that children with one bipolar parent will also be bipolar is about 25%. At least you know very well what the signs are that you need to watch out for. Good luck.