Complex sentence: It was founded in 1891 as the Church Lads'Brigade with its sister organisation, the Church Nursing and Ambulance Brigade for Young Women and Girls, later the Church Girls' Brigade, founded in 1901.
Split into simpler sentences: It was founded in 1891 as the Church Lads'Brigade. Its sister organisation, the Church Nursing and Ambulance Brigade for Young Women and Girls, later the Church Girls' Brigade, was founded in 1901.