I would make a budget and see where the "extras" are. For us, there are always things that could be cut out. And don't forget, as the other poster mentioned, to exclude your work expenses and see how much money you are saving (gas, clothing, dry cleaning, day care for the baby, etc.) Both of our vehicles are paid off and old (one is 8 years old and the other is 13 years old). As the other poster mentioned, cable tv, cell phones, gym memberships, etc. can be eliminated or down sized (premium cable vs. basic cable). Also, I see a huge savings when I buy "real" food vs. processed food (and it is better for you).
I feel like part of my job as a stay at home mom is to find the best deals, ways to save money, etc. By staying at home, I have time to do this.
And sell stuff on ebay.
Good luck and I hope that it works out for you!