Id start with feeding in her actual enclosure, alot of snakes get stressed out when they are moved and will cause them not to eat. Time of day shouldnt matter. It definitely wouldnt hurt to try to switch to F/T because its generally cheaper and more convenient. As far as prey size consistency, Ive heard of people getting them from various websites (unfortunately I do not know any) but im sure you can google it. until then keep trying a little bit longer without making any significant changed to what shes used to and then try a size down in prey before doing anything more drastic.
EDIT: How long has it been since shes eaten last??