every 5-7 days is good for a hatchling & youngster. when i got my girl she was eating every 7 days, then at about 8 months old we went to 10 days & now at a year old she's still going every 10.
every snake is different though.
just keep in mind that it takes 2-3 days to digest a good sized meal & you cannot do any handling during those days or your snake may regurgitate & thats bad for them.