The figurative language here ( ‘A tree my baby brothers could lean on’ and ‘the raft that helps carry them over this life’s rough rivers’) Tells me that the writer of this poem is needed to be a ‘breadwinner’ for the family. This can be enforced by the fact that the poem states the family only consists of ‘Mom and us kids’, The author is now tasked with duties such as caring for his baby brothers once his mother is no longer able to. Families without 2 parental figures is normally very straining to the kids and the single parent, only the strongest can withstand the onslaught of caring for kids. Thus letting me know that the meaning of this poem is that family needs to be there for each other because no one else would.
The purpose of personification in the above excerpt is to give human characteristic to death which is considered to be a non human. Writers usually use personification in their write ups in order to bring an inanimate objects to life so that their actions and natures will be better understood.