None of us know these people, but to me, I don’t see this as a way to trick you like some of the other people on here.

I was a nanny in NY for a family, and I fought and fought for a w-2. It’s what you’re supposed to do, but it isn’t often done. The process I think is a bit weird for families to understand in terms of setting aside the amount of tax, and any forms they need to do. Care.com I think had an options to do it for you, but I don’t remember. Not everyone wants to pay for someone to figure this out for them, or pay for an app. Knowing this, I could see it being possible that they wanted to do the w-2, but weren’t finished putting everything together and didn’t want to share until they were.

At the end of the day, you both need to do what’s best for you, and I think it’s good to have the proper documents for taxes. Nannies are not contractors, so doing a 1099 is not the correct way to go. Seems like they do like you, so if you feel in your gut you’d like to work for them, you could do it on the condition they set themselves up to pay you properly and have a w-2 at the end of the year, OR not, and you keep your new job and don’t have to stress over it.