I think this is another difference between European and Brazilian Portuguese. In EP "levantar" is used non-reflexively where BP would use "retirar" ('to fetch, in English). In EP "se levantar" is used where BP uses "levantar" ('to get up' in English). Any learner not aware of this and not aware whether the source is EP or BP is likely to get confused!
Brazilian takes both levantar and levantar-se as the same = "to get up". (unless there is another object)
Ela levanta às seis = ela se levanta às seis = she gets up at six
Ela levanta pesos = she lifts weights
As far as I know, "retirar" has nothing to do with fetch. "Retirar" is "remove - take off". For persons it is used with reflexive, meaning "go away" or "go to sleep".
Amigos, vou me retirar = friends, I'm leaving/going to bed.