By all means, don't ignore this family. It's tragic when people from other countries come here to study or work, and end up feeling no one cares about them or wants to be their friend.
Instead, do all you can to reach out to them and let them know you care and want to help them. In other words, the most important thing you can do is to be friendly! After all, if you were in their situation, wouldn't you feel lonely and want someone to be your friend? Remember Jesus' words in what we often call 'the Golden Rule': "In everything, do to others what you would have them do to you" (Matthew 7:12).
What can you do? Begin by calling on them (perhaps with a little gift of food, or small toys for their children. Avoid, however, anything that might be misunderstood, such as food they wouldn't eat in their culture or toy weapons.). Offer to help them with transportation, or babysitting, or make suggestions about places to shop. Don't overwhelm them, but do ask God to help you be their friend.
In addition, ask God to help you reach out to them the same way He has reached out to us -- in love and understanding and compassion. Seek to understand their needs, and learn more about their country and its customs. Most of all, ask God to give you opportunities to share the good news of Jesus Christ with them, both by your words and your example.