When is the right time to attend grad school? Is there one?

Dear Flutherbies,

I’m a college graduate who has long dreamed of being a high school English teacher. It’s my passion—to impart the same love of and excitement from literature that past English teachers and professors gave to me. Each of them was so fiery about what they loved that it rubbed off, and my already prodigious bibliophilia grew into a career aspiration. Surprisingly, I didn’t major in English because I thought a more “practical” major (in my case, journalism) would serve me better. Midway through my senior year, though, I knew without a doubt that I never, ever wanted to be a journalist: years of slaving away to the paper had drained my soul of any joy in news.

I’m young, married, happily (and gainfully!) employed, and keen on starting a family within a few years’ time. My problem is this: is it financial suicide to consider attending grad school, even part-time, when I have a well-paying job that I really do love? This position is everything administrative that I adore; the company is fantastic; the industry is guaranteed steady (healthcare/geriatric care); the people are sweet and fun and all just good folk; I make enough money to support my husband and myself; and they would be happy to have me forever. Do I want this, or do I want to spend boatloads of money on more schooling to enter a profession that a) pays in breadcrumbs if at all and b) is hardly in demand anywhere?

I’m not asking for psychological insight. I know that I love English, love literature, and love kids. I’d be a great teacher. My question here is, is there a more sensible track between the two choices presented here? Employment and stability in a position that I love and am immensely grateful for, or creative fulfillment in an educational track that won’t necessarily guarantee work?