King Robert I (VII) of Scotland
Robert was born in 1274.  He died  due to leprosy at the age of 55 in 1329.

 Isobel de Mar
Isobel was born in 1278.  She died at the age of 24 in 1302.

 Marjorie de Bruce
Marjorie was born in 1297.  She died at the age of 19 in 1316 in Renfrewshire, Scotland.