Work Dilemma!

[AlphaFrog]

Ok, I've been at my current job (Office Mgr for a small family business) for 6 months and I want to start by saying that there's absolutly nothing wrong with the job itself. However, I have been offered an interview for a full-time postion at my part-time job (I work at a nursing home on weekends). They already know what I make at my current full time job, and the personnel director told me that "You never know what Amanda (the Nursing Home admin.) can do". I haven't gotten a firm offer (I would find that out in the interview), but they indicated they would be offering at least $1/hour (yes, I'm hourly, it sucks), plus their benefits are 1000% better then where I'm at now. Also, it's about a 20-min less commute. Another thing: where I'm at there's ZERO chance for advancement, where at the other one, I would have ALL KINDS of oppertunies to advance.

Here's the full weigh-out:
Current Job:
Pros: I like my boss and my actual job. She's paid for me to become a Notary (which I would definatly feel obligated to pay back). I know this job well, and it would put her in a huge bind to find someone new. My boss now treats us like family.
Cons: NO BENEFITS, longer commute, less money

Potenial New Job:
Pros: More money, better benefits, MUCH shorter commute, 100% better chance of advancement
Cons: Less "stuff to do" (I like to be busy), I would put myself in awkward postion with old boss and leave her in a HUGE bind.

Any thoughts???