(Not sure if this is the correct place to post my particular question, so please inform me if I am wrong)
Right now, I am a stay-at-home mother to my 15 month old daughter, Kyleigh. My fiance is the "bread winner," as he takes care of ALL finances. (LUCKY ME!

)
I babysit my 3 month old niece for $10/day (3 days, at most, a week)
Recently, we have been running into money problems and I have decided to raise my price to $20/day. Right now, he owes me $140 for back daycare.
(I had previously negotiated to babysit in exchange for 2 diamond rings he had to sell, up until Christmas. I gave him the rings back because he wanted me to also take on the rest of the payments IN ADDITON to watching my niece for free. So he has known that he owes me $140 for a week 2 days)
What I was thinking about doing was advertise around my community that I have 3 slots open for child care in my home. (I say 3 because that is the maximum amount of childcare I can legally provide without a daycare license)
Having a 15-month old daughter at home already, how much should I realistically charge per child, per day/week?
I didn't want to charge too much, as most residents around here are low-income. I kind of wanted to offer a break in childcare costs. There have been a lot of instances of death due to leaving children in hot cars while parents are working inside.
I was thinking $25/day.
Any ideas would be appreciated