If possible, I would accommodate them and extend their lease for an extra week if that is what they needed.

Not to discourage you further, but CA has so many little intricate details to running a business with lots of extra taxes or fees.

It also costs extra for maintenance and security.

There is a component of doing a cash-out refinance, but it seems the thought would just be trading one loan for another in that case for an extra ~$5k of leverage. 

I would rent the extra room(s) similarly to a medium term rental property.

Raise your size limit and charge extra $$ with pet rent. 

We wanted to do LVP throughout the house and the kitchen and bathrooms had an extra layer of plywood to raise its height so we had to manually crowbar it out, which took days and a lot of work.Aside from the flip, we didn't expect the sellers too keep changing their minds on closing date.

But that is just with our occupancy rate, posted rules and extra fine for breaking said rules (spilling drinks, food, dirt, etc.).But only you will know how often it needs to be done.

She asked if she could pay $100 per month extra towards the deposit .

You could just think of the parent Series LLC as the ASSET HOLDING COMPANY and the traditional LLC as the OPERATING COMPANY.It would require extra costs, since you are involving the formation and operation of an additional entity.