Find out if any fellow students have spouses who stay home. It is less reliable than a licensed daycare, but it should be less expensive.
If your wife gets a full time job, see if you can set up a dependent care FSA to reduce your post-tax costs. Some employers even contribute (my wife's employer contributes $1 for every $4 she puts into her dependent care FSA - it's not much, but it's an extra $1,000, and it's pre-tax). I'm assuming you have done this at previous jobs, but it's a good idea if you haven't.
Does your state offer childcare assistance? Depending on what your wife makes, you may qualify for reduced daycare.
Increased loans are an option -- unhelpful financial aid people should eventually know how to answer your question. You're not the first family to go through, nor are you the first person to ask for more cash.
Best of luck! PM me if you have further questions
The grass is always greener