Puzzle 029: How Old are the Children?

ナゾ０２９　子どもたちは何才？
友人から次のような手紙が届いた。
『昨年３月に女の子が生まれ、上の
お兄ちゃん、お姉ちゃんと、３人
全員の年齢をかけ合わせたら３６、
足し合わせたら１３になりました！
みんな元気に育ってくれて嬉しい
限りです。　　　　　４月２５日』
さて、その手紙にある子供たちの年齢
はそれぞれいくつだろうか？

Google Translate
I received the following letter from a friend. 『Girl born in January last year, on the brother and sister, we took three fit everyone over the age of 36, brings the total reach 13 now add! It is fine as long as I'm happy that everyone grew up. April 25 』Now, in the age of the children is what some of their letters?

Notes on Puzzle
A math puzzle with people's ages, standard fare. Three people; when you multiply their ages you get 36; when you add their ages you get 13. You already know the age of the youngest (it is given in the letter; if the youngest was born last March and the letter was written in April, then she is 1 year old) so it's pretty easy to figure out the ages of the older brother and sister.