It's quite amusing to think that The Woman in White is essentially the Victorian equivalent of the airport novel. It's a "sensation novel" about two sisters who find themselves in the clutches of the dastardly Sir Percival Glyde; their only hope is the existence of a mysterious woman dressed in white who holds the key to a terrible secret...
There are all kinds of weird and wonderful twists and "sensations": mistaken identity, secret societies, True Love and High Adventure. The fact that nothing in the second half of the novel makes any kind of coherent sense is, of course, neither here or there. The Woman in White is the best that the Victorian sensation novel had to offer.
I have to say that I became heartily sick well before the end of all the sickly women! The strongest of them could barely go for a three-mile walk without being confined to their bed for the next day and a half! Compare this to Dickens' heroines - Lizzie Hexam, who underwent poverty and hardihood every day of her life and was never ill; Amy Dorrit, ditto - and you can see that this isn't Victorian sensibility, it's Wilkie Collins being really, really sexist.
The Woman in White is amusing enough for its intricate if occasionally clunky plot, and the delightfully villainous Count Fosco - but do bear in mind that Victorian literature has so much more to offer.