because of that, foster grandma sandy hadidea an a book. >> i felt like, it's a story that needs to be told. in addition to cute pictures. the good that they've been able to do for each other. and for foster kids everywhere. >> reporter: the proceeil to a non-profit that supports foster caregivers, like buddy's foster mom,cary lewis. >> foster care has be hardest but absolute best thie ever done. >> reporter: there are more than 400,000 foster children in the unitedtates. with more than 100,000 awaiting placement. the pictu aot? about lo?mve, and joy, an >> it's such a? porful connection?g. >> reporter: who knows? mayb9i?e you know a dog friend.ds a new harry smith, nbc news. >> can't get enough of those pictures. for us on a tuesday night. i'm lester holt. for all of us at news, thank you for %0s? watching and >> announcer: two sisters suffering from a chronic condition putting their lives at risk. can an intervention cause them to change. >> i want to hear you say it! >> i am committed. >> i am committed! >> announcer: rosie mercado's delicious new diet that will have you wanting -->