She is acting entitled. I wouldn’t compromise. Since you’re her employer, you have full control over what she does and doesn’t do at work. If she wants to keep pushing you (and your partner continues to allow it), I’d have an attorney write up a buyout agreement. If they want to run the salon into the ground, they can buy you out and make all the bad decisions they want, but there’s no reason your investment should be compromised because they don’t know how to treat the business like a business.

As far as liability, you’ll need to refer to your state board guidelines and your liability insurance company. (Typically, liability falls on the renter, since they are self-employed and doing business under their own business license, but some states assign penalties from the board to the holder of the establishment license.) That said, I’m not sure you have any legal grounds for prohibiting them from hiring any employees they may require. The freedom to hire/fire workers without interference is a key factor that separates a self-employed person from an employee. Your attempt to prohibit that may be construed as an inappropriate degree of behavioral control.

Only employees are protected by the Family Medical Leave Act–and renters are self-employed. Just as a salon owner wouldn’t be exempted from paying their rent on their building during a medical leave, salon renters wouldn’t be either, as you have no legal grounds to expect it. (Typically though, a lot of salon landlords will temporarily suspend the lease in those cases. They’ll likely rent out your space to someone else in the meantime, but they tend to be more flexible than their own landlords are, especially if they want to retain a quality tenant.)

Unless your state has commercial landlord-tenant laws (most don’t), you’ll have to refer to your contract with the owner. I’d argue that periods of closure that are outside of your control aren’t ones you should be paying rent during. You weren’t given the opportunity to choose the contractor, to determine the length of time the facility would be inoperable, or whether to forego the work altogether. If you had, you would have been able to plan for the closure accordingly or have the work performed in a way that reduces the inoperable time. How are you expected to offset your personal and business expenses during this closure?

I don’t agree that you should be paying rent during the renovations at all, but unless your contract has provisions against this kind of thing, there may be no recourse. If it’s just a few days, it may be better to let it go, but if you’re looking at extended closures it may be worth speaking to an attorney about the possibility of seeking reimbursement or getting the rent waived entirely.

You need to contact an attorney with a specialization in employee defense (employment law) immediately. It sounds to me that you and your coworkers were misclassified. You cannot be “hired” as a booth renter and a “manager” isn’t a renter either. Read this, this, and this.