Here's some other things...if people are really low income, they can qualify for assistance, but you'd have to get certified. You might want to check into if that's possible. Also, if you're certified, you can get on the food program, and get paid for feeding even breastmilk, as well as paid for feeding your own kids. And if you're low income, then you get more, like $4 or so per kid per day. Doesn't seem like much, but adds up fast to help you out financially. And what are the rates in your area? If they wouldn't be able to get $125/week for an infant anywhere, then expecting you to do it is ridiculous. It should be a decent price for both parent and caregiver, taking everything (age, care provided, etc.) into consideration.
Also, is there anything they could barter with? Perhaps they could help you in some non-material way? It's important that they value what you're doing or you WILL be taken advantage of soon. People can't really help it, if they don't appreciate something they take it for granted.
I do think, though, that you want someone with similar parenting philosophies. Part of that, though, is someone who values their child. And there are so many who make it work, either working part time, bringing their child to work, working different shifts, etc., that unless it's a single mama I sometimes don't trust people who say they'd love to stay with their kids but don't work it out somehow. Just had some bad experiences with that when I was doing in home childcare, and it starts to show on the kids...kids reflect the love they get, and if the child isn't truly being valued, then they won't be as happy. Your heart will be totally involved, though, and soon you'd do anything for this child...but at the sacrifice of yourself and your own children.