Ivanka Trump and husband Jared Kushner have welcomed a baby boy into their family. "We just welcomed a beautiful & healthy son into the world. Jared, Arabella and I couldn't be happier!" Trump tweeted Monday shortly after the baby was born. The new baby is The Celebrity Apprentice star and Kushner's second child and the fourth grandchild for Ivanka's father Donald Trump. Arabella, who is currently 2-years-old, was born in July 2011. Ivanka, 31, announced she was expecting baby No. 2 in early April. "Jared and I are so excited that Arabella will become a big sister this fall. Thanks for all your good wishes! xo Ivanka," Ivanka tweeted at the time. Ivanka and Kushner, the owner of the New York Observer newspaper, began dating in 2007 and wed in 2009. Donald Trump Jr. and his wife Vanessa are the parents of two children -- Kai Madison, a 4-year-old daughter, and Donald Trump III, a 2-year-old son.