This is covered in
Chapter 118A of the Nevada Revised Statutes. As stated by ballengerb, it seems the only guidance given on the amount of late fee is "reasonable". There might be case law on the regulation, which you might be able to search on NOLO or ask a legal aide.
In California, they have a similar regulation, "reasonable", but there is case law, and a little more direction in the regs to prevent landlords from charging a rate that is "retaliatory". The fee needs to represent the ACTUAL cost of receiving the rent late like the incurring of late fees from the bank.
Lawyers here in CA suggest $25 has been considered fair by CA courts. I wonder if the same sort of guidance has been created in NV. Fr_Chuck is accurate, the landlord is responsible for repairing the window.