Can I get in legal trouble for being paid an exempt status salary as a full-time live-out nanny?

I'm a licensed elementary school teacher who has been working as a full-time live-out nanny for 3 years. Last year we renegotiated my salary from non-exempt hourly pay to exempt salary. I found out in 2014 my employer wasn't tracking my OT hours when I called her out for underpaying me one week. I hadn't either because I assumed it was her responsibility based on the information I was told by our nanny agency and what I've read online. After several attempts to begin tracking my OT myself (over the 10 hours per week I normally work due to my set hours 8:30-6:30) I found it burdensome and difficult to remember to track hours so we agreed when my employer had another child to pretend I'm exempt. I do not get OT or my babysitting fee during the week and my employer did not amend my initial contract even after I insisted. Should I insist again for a new contract? My verbal 3-year commitment is up. I need a significant raise but need to know if we sign a new contract or amendment based on illegal employment status if I could get in trouble. Please note my employer is an attorney.