My daughter had precocious puberty and we were spinning trying to help her deal with all of the emotional symptoms that go along with the physical. We survived her teenage emotions beginning as a kindergartener. She was able to excel in physical activities at a very young age because of her 'development' and was an all state athlete in a couple of sports in high school. In college she was exceptional as an athlete. We took a very hard and confusing diagnosis and turned it into something positive for her. What I was not prepared for was that in her early 20's she was diagnosed as bi-polar. I believe this is due to her precocious puberty at a very young age. Again, we made it through, although it was very difficult and confusing. My advise, seek help through counseling and keep telling them you love them. She was very confused and out of control... talking with her now, she said our constant love and support is what pulled her through. She was at very dark times multiple times. She is now a functioning and healthy young woman, who I still watch very closely knowing the bipolar could rear it's ugly head at any time. Mom's love goes deeper than any other... go with your gut and don't stop seeking medical help until you find a doctor that will listen to you.
I am not aware of the link of seizures and precocious puberty, but I do know the puberty issue and that can be a pituitary tumor (usually benign as in 99.9%) or genetic conditions. The magic foundation in Chicago is a good resource for this and they will also have doctors and other parents for you to source.
Another place to source is NIH in Maryland as they treat children, often free, usually as part of studies. That would be dr stratakakis usually.
I hope this helps. Not a doctor so just giving you my patient point of view as a fellow pituitary patient.