47yr old f with anemia. taking iron and centrum vitamins but still feeling very sleepy and tired...what can be the cause?

Could be comorbidity: The anemia may be an issue, but thyroid, and vitamin deficiency issues could be considered. You could possess a sleep disorder such as sleep apnea, and perhaps you are taking medications which are affecting you. Talk to your doctor as maybe this needs to be pinned down.

As above : If she still anemic or have another medical or mental issues , than it is normal to feel that . It is important to do a detailed evaluation to r /o medical abd mental health issues . In addition excersize may improve her energy.

Many reasons . . .: I assume that you, the 25yo female, are writing on behalf of the 47yo female. Regardless, there are many reasons for being sleepy & tired besides anemia. Depression comes to mind. Sleep apnea leads to poor quality sleep despite adequate quantity. Under active thyroid (hypothyroidism) can lead to fatigue. So can heart failure, kidney failure, liver failure, etc. 47yo female needs to go see her doc.