The java fern, java moss, and anubias would probably survive. The plants that require more light most likely wouldn't be happy after a week of (relatively) no light, but they might not be beyond redemption.
Buying a timer is important yes but do I think you should spend your last bit of money on a timer , NO. Sure you want to protect your investment but what happens if you spend that money and your kid(s) get sick and need tylenol or something and you just spent your last $$ on a timer for the tanks. Do you have a landlady or something that could swing by and turn them on or anyone? I know you already said not really but there really is no one? An aunt, uncle cousin, neighbor, in-law anyone?