'Susan had come into the bedroom and 'then' - (wstawila bym 'then', dlatego, ze to dopiero w tym momencie - to tak jak po polsku, 'i wtedy') ('she'-mozna ominac, bo o Susan mowa, to kazdy sie domysli) realised 'that' ('that' - duzo ludzi omija, ale w sensie gram to powinno byc) she had forgotten to switch off THE lights in the kitchen'.