if you mean will they be born and just know how to cast a circle and create potions? no, you need to teach them. if you mean your kids will have better casting ability because you are a witch, maybe. it's the same as if you have red hair and the father had black hair, they run a chance of being born with red hair, but they could also have black or brown hair. because you're form a family of witches it doesn't give you much of a better chance to be skilled with magic. it gives you some, but not a lot. the plus side, your kids can learn from you, so they can have more help then you did if you're first generation witch. just keep in mind you shouldn't force your kids into being witches [i also mean Wiccan when i say witch] they should choose for themselves.
I am not sure about the science of it but in my family and in the family of some of my friends there seems to be patterns in magickal interest through the family's history. Many of the female members in my family have been drawn to Paganism and the idea of magick. My own mother was a Pagan for a large portion of her life and never told me. I eventually became very interested in Paganism and that is when she revealed that she had been a Wiccan for a long time but converted to Christianity shortly before I was born. I'm not sure if it's genetic or what but something in my blood drew me to magick. I wasn't born "good" at magick or anything like that but I did have a pull towards it.
It depends on how much ability you personally gain.
Just casting magick won't do much of anything for your hereditary line.
But opening up key blocks that most of us have to the spirit realm is a genetic thing, and your kids would have a chance of inheriting it. However, a blocked spiritual state is also passed down, and I don't know which is dominant/recessive. :P