I've been out in the work force for about 3 years. I recently just got offered a new job with a very well regarded company in the industry that I work in. The experience would be great and I really want to accept the offer (would be starting mid Feb if I give in my 2 weeks tomorrow). Oh and the money is better too

I feel guilty though because of my Harvard acceptance and my plan to leave in 6-7 months to attend law school. I obviously didn't mention any of this during the interview process and I'm worried that leaving in such a short period of time could potentially damage relationships when I leave.
I'm wondering how this will look on my resume to future big law employers? I'm sure the experience will provide great talking points, but what about the short time period? For reference, post college, I have been at one company for about 1.5 years, current company for 1 year, and this new job would be only about half a year. Will employers think I'm a disloyal millenial who jumps at new exciting opportunities? Will I have to provide references from this new job (if I'm unable to leave on the best of terms?).
I'm not sure about defering a year. Currently I'd rather not because the oppurtunity cost of leaving employment for lawschool will only increase as time passes by. Also, increased age won't affect my fin aid positively because parents financials are a non-issue.