I love this question and idea in general.
Lets face it, most of the public at large think people that actively trade for a living are nuts and are usually against you. They all think you're going to fail and the odds are certainly in favor of that assumption. Why? Well, most traders do fail eventually. Also, for the same reason many people here on Elite Trader heckle and belittle those that claim or tout success. Unfortunately, it's human nature, ever heard of the saying "misery loves company"? Far too many people would rather drive to work everyday and spend 8 hours or so tasking at an activity they absolutely despise. They'd rather mortgage their lives for a paycheck of which they overspend on stuff they don't even need (Fight Club 101). But hey, they don't call it work for nothing.
Now, when your family gets in on the act, it can be hard to stomach indeed. First of all, you have to accept people for what they are. My Dad (I love him and he's been fantastic my whole life) spent 33 years in a mine and retired a production plant supervisor with no higher level education. He is definitely a hard worker and smart person. He instilled in me an unbelievable work ethic. My Mom is a successful business person in the world of art and antiques. She also has an unbelievable work ethic and no formal higher education. Now, both wanted me, their baby, to get an education so I wouldn't have to work like a dog like they did to get ahead. So I got my education, trudged off to work in the corporate world. Secured a fantastic job in one of the worlds largest pharmaceutical companies and was absolutely well compensated, but totally miserable.
Now, you think both my parents were supportive of my desire to go into trading? Absolutely NOT! Luckily I do have a VERY SUPPORTIVE fiance that helped me with the switch to becoming a successful investor/trader/business owner. Now, it's very hard when you have no support or very little, but that's why it's the toughest mental game in town. Recently I asked my parents, both know I am successful in what I do, if they wanted to invest in my business. Both, without batting an eye said, NO! Wow thanks for the support Mom and Dad, but hey, it's just business. Can't take it personal, and I don't.
At a certain point you must be honest and true to yourself. If you are going to take it seriously and "know" you can do it (you will KNOW if you are honest with yourself), then at some point you have to take the step or just keep on keeping on. At some point you must do what it takes to tune out the noise. Have a heart-to-heart with your spouse/significant other. Agree upon some realistic goals. Stick to them and be honest with each other. As far as in-laws and friends, they're the easiest to tune out. I have a friend that reports the the cubicle each morning and what I do I know just drives him up the wall. This is the same guy that also says that if he worked for himself he probably wouldn't get out of bed in the morning. Hey, at least he's honest! Success speaks loudest, and believe me , if and when you do become successful, you're going to find out very quickly who are your TRUE FRIENDS.
Good luck, it's hard, but being open and honest with your closest loved ones is essential. If you get no support after that, then you have to make a personal call and assess your priorities and relationships.