[ Encourage and interact as a family]
The idea of encouraging the students should be highest priority of the parents. It's a new environment and they're not sure what's going on - it's important them to recognize that they have a loving family. It's also important to interact as a family in terms of learning English. Te entire family is going through a life-altering transition and it will be much easier for everyone to be able to relate to one another.
Try to speak more English at home or maybe have a night or two out of the week where the entire family will sit together to play games (in English!). This kind of interactions is just what you would expect from normal families - don't change up the dynamics of your family. It has been enough of a change moving to a new country and stability is an important issue.