Is there a Leave Act that allows a National Guard spouse to take time off work while the Soldier is at a month long military school?

Yes. FMLA should cover that. My wife has used it several times. There are some guide lines for it but it is meant for this.

Federal law says you'd have to be deployed or on active duty for contingency operations. Source: https://www.dol.gov/whd/fmla/2013rule/FMLA_Military_Guide_ENGLISH.pdf

Hopefully there's a state law that can help you out.

While I understand this is a hardship, it is one that both you and your wife were aware of when she took a job working nights and attending nursing school with the additional hardship of taking care of children. With all military training requirements, you have a timeline of when you would progress in your career and be due to attend trainings - these are only 2 short trainings of 3 weeks each with a break between them. What would you and your wife due if you were required to deploy short notice and would be gone at least 90 plus days. I am not trying to seem harsh or uncaring, but as a military member (not just guard member) you signed up to get the benefits of the military, but also with the knowledge that you would have to give up time with family, and for a guard member from your civilian employment. What would your wife due, if you were required to deploy - would she have to quit work, drop out of classes for that time frame, change work schedules, arrange for familty and other care providers for your children. These are questions that you as a military family have to address - for both short and long term military duty. I agree with other responses that you should check with your unit JAG office to see what federal or state laws would be helpful in the situation. If you are planning on staying in the guard for the whole 20 plus years or until age 60, this type of situation will come up again and again. I have been there as a single parent and had to go to both my 3 and 7 level training for 6 weeks each. I had to have family to take care of my children so that I could attend. But this was something that I was told when I requested to cross training - so I knew about it and could plan for it. Please everyone that is reading this - take a good look at what your military unit training and career education training requirements are as you would for your civilian career - what do I have to do this year, in the next 5 years, etc. What hardships will my absence from home and/or work suffer due to my required military duty? If you show, the military, your employer and your wife's employer that you have these requirements and this is how I think we can make it work in the best way for all of us. Not to say that it will be equal - your spouse is always going to have to give the most in the situation. It is just a fact of life in the military - no matter if it the branch, active duty or a reserve/guard member.