Due to Covid, in general USCIS is limiting entrance to their offices to beneficiaries and anyone listed on the appointment letter.
Some field offices will let you bring the baby and some won’t.
Does petitioner or you know anyone you would trust to at least ride with you three to the parking spot by the field office and wait in the car with the baby?
This way you won’t be separated for long. If USCIS lets you bring the baby with you, then you can send the sitter home in a ride share or taxi.
Tammy.T reacted to Mike E in Does anyone know if they can bring a baby to the green card interview?