前面An amateur potter herself是用来修饰accountant,后面complicated as they were by his unusual system of record keeping修饰his business accounts(指出由于艺术家不同寻常的记录的方式,使得帐目很复杂),句子的主干是the accountant offered to help the artist with his business accounts,即那个会计提供帮助,帮艺术家关于他经济帐目这一块.