The answer is money. How Much? While there are no absolutes, a week or two of income is very standard. The longer a nanny is with your family, the larger the gift.
Creative and thoughtful add-ons are great. Consider items that promote self-care, in addition to handmade gifts from the kids. If your nanny has children of her own, definitely consider asking if there are gifts they would like.
2020 has been difficult for everyone. For families that are able to, now is a perfect time to recognize and show appreciation for the person taking care of your children and helping provide some normalcy in your day-to-day life.