friends. they'll protect and calm you. and join in on some of the fun and appreciate the history. and this. cherish your animals, because sometimes you'll need the quiet comfort that only animals can provide. their most important piece of advice years ago? our dad, like yours, is a man of great integrity and love. remember who your dad really is. >> it's really an exclusive club among presidential children. and they do keep in touch. there's an empathy there because they've all been through it. and no one knows what that's like to be in that kind of public spotlight when you're so young. >> in their new letter, jenna and barbara bush told sasha and malia how they watched them grow into impressive young women with grace and ease. they remarked how they were glad the obama girls had each other as the bush twins did. their letter encouraged the obama girls to hold onto the memory and emboldened them to chart their own path. >> explore your passions.