What causes a brake fluid leak that drips from in between my front wheels?

To answer your question.... Look at the bottom of the brake booster..that big round thing behind the master cylinder...or rub finger under it to see if fluid is present.. Also possible metal crossover brake line but less likely! IF fluid is present under booster... Suspect master cylinder internal leak!!

Might I suggest bringing that in for a professional opinion. We would be glad to have our master tech look at your vehicle and diagnose that for you.