Heather, You need to come up with a "set" fee and charge them. You are providing a service, therefore, the parents need to pay for said service. You are providing your time, space, electric, water and heat to work w/these children. You can't do it for peanuts. Come up with a payment plan that is reasonable and advise them that it's a new year and your fees are going to be said price and do not waffle on that.
If it will help you, you might want to check around to see what other home school teachers are charging for services. Don't sell yourself short because believe me, the parents are getting educations for their children for little cost. Is that fair to you? No. Start putting yourself first and don't worry about them leaving. If they do, they'll be back because you are by far cheaper than other home school teachers.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
