It is a tough situation.They are neighbors and you will see them regardless.Can you talk to the Mom without the children around?Maybe suggest a coffee out.I would suggest to Mom that she send the daughter to before and afterschool care.That way when the girls see each other it will be "fun"hopefully.I would expect that if there is before and after school the other child will make some friends.Explain to Mom that maybe its a lot to move and go to a new school ect.

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