OP here. Thank you all - you've been really helpful.

I just read the FAQ on the new MoCo law, and as long as the leave you currently provide can be used for the reasons given in the law, you don't have to divide it out or offer separate leave:
http://www.montgomerycountymd.gov/humanrights/Resources/Files/MC_Earned_Sick_Factsheet_updatedJune2016.pdf

We originally offered 5 days of sick leave in addition to 10 days of vacation leave. In my job, sick leave is only for unexpected illness. We ran into the issue of our nanny assuming she could use the sick time for additional vacation if it wasn't used for sick leave, when we intended it more as an insurance policy in case of serious illness. I mention since you say the lower amount of leave would include greater flexibility. If you really intend the sick leave to only be used for illness, Id clarify that in a contract. (Of course people can lie, but that's a separate issue.)

You might want to also consider bundling all leave as PTO. The upside to this is you can budget the exact amount of leave you can afford to offer. The downside is that you need to be clear on your limitations if it is all used as vacation with no time left for true sick leave.

Finally, be sure to clarify how much, if any leave, you will pay out in cash and how much, if any, can be rolled over.

Your paragraph is clear and pretty much the way we structure it.

We give 15 days total. The idea is 2 weeks vacation, 2 floater days and 3 sick days, but we don't break it down that way. If our nanny needs a mental health day I don't want them to feel stuck if they've used up all their sick days and want a vacation day or whatever. We call it All Purpose Leave and just as for as much notice as possible.

That's helpful - thanks. Yes, we offer 5 days of sick leave also. We had been considering switching to just 12 days of personal leave total, but that seemed confusing to people (and of course it's fewer days, but greater flexibility). We're in Montgomery County so addressing some of the new specificity of the Sick and Safe leave act seemed to be easier w/ sick leave still broken out.

Most of that sounds good. Do you also have additional sick leave, or is it all rolled together? Here is the language from my contract (it's all "her choice," so that part won't work for you):

12 days paid off per year which accrue 1 day per month for vacation, sick or personal days. Additional time off, or time off before these days have been earned, will be unpaid. There is some ability to adjust the work schedule to make up for any unpaid time off, or to accommodate appointments requiring fewer than 2 hours off work if you would rather not use paid time off. Please schedule time off at least two weeks in advance (not including sick days).

It doesn't say so here, but she is required to take it in half day increments. Sometimes that means extra hours in her check if she decides to use a half day but is only out for a couple of hours (I'd rather pay her the time than try to find coverage).

The other option, and the one I'm planning to switch to for my other employee who doesn't have the same schedule every day, is to track actual hours. So it's not .83 days, but 3 hours, and she earns 8 hours of PTO a month vs. 1 day.

Can anyone share simple contract leave language you have used or liked?

Something along the lines of "Paid Vacation: 10 days (2 weeks) per year. One week of vacation is to be scheduled based on the families’ vacation schedule. Vacation leave will accrue at the rate of one day per month, until the maximum of ten paid days is reached. Vacation leave may not be taken in the first three months of employment. Employee is asked to provide one month notice to request vacation time of more than a day."

I don't really want to bother w/ fractional days (.83 days accruing each month) as that seems overly fussy. And I wouldn't expect someone to have to wait until their last couple of months to have their full vacation time available either. Nor do I want someone taking two weeks off when they haven't even established themselves in the position yet, or to ask for a week off with only a week or two notice.

So I'm looking for advice on ways to phrase this that are clear, fair, and easy for all sides.

Thanks!