Soon, trembling with her soft and chilly nest, In sort of wakeful swoon, perplex'd she lay, Until the poppied warmth of sleep oppress'd Her soothed limbs, and soul fatigued away; Flown, like a thought, until the morrow-day; Blissfully haven'd both from joy and pain; Clasp'd like a missal where swart Paynims pray; Blinded alike from sunshine and from rain, As though a rose should shut, and be a bud again.
Madeline's in bed now, and the "dream awake" feeling Keats brought in during the last stanza gets amplified further.
Madeline doesn't seem to be either fully awake or fully asleep, but rather in some weird in-between stage, in a "wakeful swoon."
Whatever state Madeline's in, it's clear that her mind isn't really there. Where she's been described as "regardless" and distracted earlier (64), here her soul has flown away, and the poem describes her, using a simile, as a closed rosebud—impervious to, and blocked off from, the outside world.
Keats tells us that she's safe from "pain" and "rain," but frankly it doesn't sound like Madeline's all that safe; it sounds like she's drugged. Her body is "oppressed" by the "poppied warmth" of sleep—poppies being the famous key ingredient in the drug opium.
For those among you who don't know who the "swart Paynims" are (no shame, it happens), this line (241) is likening Madeline to a prayer book ("missal") that's shut up tight, as a Christian prayer book might be in a land where dark-skinned ("swart") Muslims ("paynim" is an old-school word for non-Christians, particularly Muslims) live (and "pray"). She's not just shut up by "praying" non-believers, though; when you say the line you also hear that they're "preying," so once again Madeline's being described as trying to protect herself from predators.