"Our son Hunter and Navy’s mother, Lunden, are working together to foster a relationship that is in the best interests of their daughter," the president said in an exclusive statement to PEOPLE President Joe Biden has offered his first statement on 4-year-old grandchild Navy Joan Roberts, the daughter of Hunter Biden and Lunden Roberts, an Arkansas woman who filed a paternity suit against the president's son in May 2019. "This is not a political issue, it’s a family matter," President Biden's statement continues. "Jill and I only want what is best for all of our grandchildren, including Navy.” "You have...