My dad is pretty smart (he doesn't have an IQ score but you know smart when you see it) and has an engineer degree and began in computers when they took up entire floors of buildings.
My mom isn't unintelligent but she was no student in her day. She has very good intuition and organizational skills and problem solving. If I had to guess above average in intelligence but horrible study skills.
My parents have two HG/PG sons...one mathy (CFO of a company) and one has a career in words.
I never had a IQ test like my brothers and always felt "less smart" than them...but other than procrastination school was pretty easy for me. I tend to think my thing is words and arts and creativity but I liked math. I just didn't live for math. I could have kept going and held my own I just didn't need it and didn't see the point. I had the ability just not the love.
I have a sister who took on the role of the ditzy one of the family but it is all an act that she turns on and off as the situation changes. If I had to guess probably above average but not gifted and it was probably a defensive mechanism living as the baby in a family with a bunch of older HG/PG kids and dad. She is also very creative/artistic with a career that uses that plus business (so math isn't scarey to her).
I don't know the answer to if your parent is Mathy will the children be mathy. I know that all of us (well maybe not my sister) could have gone as far as we wanted to in math but only one had the love to follow that path and we all had different strengths.