Are Foreign Helper Contracts Fungible to the US?

We hired our foreign helper while living here in Taiwan.
If we were to move to the United States, would our contract with her still be good? We would have to get her a US Green Card? I imagine that’s prohibitively difficult?

Does anyone have experience with these types of issues?

You would have to follow US labor laws, such as minimum wage.

I guess you would need pay a lot more as local wage rules means higher wages as well working hours, such as 35 hour work week or what ever is the rules there (35 was in some EU nations)