。
She doesn't know even the simplest thing about science.
Literal
She [topic-は] science [regarding-に関しては] any-kind-of simple thing [even-さえも] not-know.
Two emphatic patterns work together. ~に関しては picks out 'as for science specifically,' setting up a contrast with what she might know about other topics. Then どんな~さえも piles on emphasis: どんな~ ('any kind of') + さえも ('even') + negative = 'not even the slightest, simplest X.' The whole sentence amounts to a sharp put-down of the subject's scientific knowledge. ~に関して is slightly more formal than ~について, and adding は makes it explicitly contrastive.