Funny how many folks here emphasize the importance of the relationship you'll have with your partner through any kind of a transition into trading.
Support of a partner can make a difficult transition easier, in any endeavor. However, as in everything else in life the path to success is only half the dilemma. Once achieved, especially in a career such as trading with its focus on money, the issue of a mate becomes even more important. It isn't easy to live a balanced life on either side of the poverty line. Add to that the very real possibility of losing half of what you make should you divorce this person and a healthy relationship takes on great significance from yet another perspective.
This leads me to my point (finally): if you want to succeed in trading give yourself the benefits of a financial and marital edge. Reduce your expenses, and in the process get to know your partner a little better. A little adversity goes a long way. Live like a college student. Eat take out pizza, drive an older car, and skip the microbrew in favor of MGD. Do this not because you have to but to see if your partner is willing to make a few sacrifices with you. More than likely you will face a time in your trading career when drawdowns will make this maneuver prudent once again and you will have already gone there. And don't quit your job until trading is providing a substantial income.