To go to a dull place abroad and live poorly, was the dismal future that threatened her: she had seen plenty of poor English people abroad and imagined herself plunged in the despised dullness of their ill-plenished lives, with Alice, Bertha, Fanny and Isabel all growing up in tediousness around her, while she advanced toward thirty and her mamma got more and more melancholy. 
To go to a dull place abroad and live poorly, was the dismal future that threatened her: she imagined herself plunged into dullness with her tedious sisters. 