I don't know about anyone else, but my days are PTO/sick days. I don't take them until the last month of the year, unless I have to due to illness or unavoidable appointments. Because my contract states that I am only required to provide 30 days notice, I inform the family on Nov 1 as to when I will be taking off in Dec. You may want to talk to your nanny and find out if she's doing something similar. She may also be assuming that she can roll them over or be paid out, and because you didn't state it in the contract, it needs to be discussed asap.

I don't know any legalities about this, but to be fair and square either offer to roll them over to the next cycle or pay them out.

If she has been a reliable and responsible nanny, it would just be the right thing to do.

Maybe set a rollover policy now. Accrued leave to now expires 6 month from now on and then whatever policy from now on goes into effect.

Some just don't take leave. Some decide to go on vacation for 3 weeks because they are going to lose it all. Really varies by nanny.

My contract states that I can roll over up to 5 leave days, but you could also pay them out if you aren't prepared to handle more vacation days next year. I would talk to her, because she may have left those days intentionally and she plans to take a long trip next year.

With no clause, how should these days be handled at the end of the year? Nanny is 3 months from the year ending and has 5 days left with no request in to use them. It's likely there will be at least a few left over.