What are the criteria that are used to decide which objects are conserved or exhibited?

'In this country' - this is an international forum. Historically, there were fewer professional artists as there was an apprenticeship system requiring boys being sent away to the studio of a master, which would not have been acceptable for girls. Angelika Kauffman was one of the founding members of the Royal Academy in the 18th century, but she was lucky, because societal expectations put women in the home. 20th century saw the flowering of independent women (the Vote, contraceptives, world wars encouraging women to go out and do 'men's work', universities accepting females and actually letting them take degrees). So it's been an uphill struggle, but we're getting there. Dame Laura Knight, Anna Zinkeisen, Bridget Riley, Barbara Hepworth, Anna Bourgeois, Tracey, Sam, Rachel - all women with work in collections. None of this addresses your main question, which has nothing to do with who has done the art, but a variety of other factors. I don't see where racism or feminism come into it.