When snakes eat big meals they are able to stick their trachea out the side of their mouth, so even if they can't easily breathe through their nose, eating big meals is not a problem. I'd say go ahead and work your way back up to her usual meals and hopefully you won't have any troubles.

Minor RI's can definitely be helped by slightly higher temperatures and proper humidity, but keep a close eye on her; if there has been much of a mucous buildup in her lungs it may not be easily dealt with without antibiotics, as snakes can't cough and dislodge mucous.

Best of luck.