Modified Memories Vs. Memory Charms

[taylorlynzie]

No: HPFGUIDX 175971

Right now I'm in the process of rereading DH and something struck me
as a bit odd, or inconsistent (whichever view you would like to take)
and I wanted to post it on here and see what others thought. Maybe I'm
just forgetting some simple fact. 

So in  Chapter Six, The Ghoul in Pajamas while Ron, Hermione, and
Harry are up in Ron's room Hermione says, 

"I've also modified my parents' memories so that they're convinced
they're really called Wendell and Monica Wilkins, and that their
life's ambition is to move to Australia, which they have now done."
pg. 96 (US)

This leads me to believe that Hermione performed a Memory Charm on her
parents and then told them about their "life". However, with some
further reading I came to Chapter Nine, A Place to Hide when they have
stunned the Deatheaters and are planning their escape, 

"We just need to wipe their memories," said Harry.
.....
"You're the boss," said Ron, sounding profoundly relieved. "But I've
never done a Memory Charm."
"Nor have I," said Hermione, "but I know the theory." pg. 167 (US)

Now am I mixing up my charms and spells and such or didn't Hermione
use a memory charm on her parents? Convincing them that they had never
had a daughter and that their ambition was to move to Australia seems
a bit more complex then just a Confunding charm or something of the
sort? What does everybody else think? 

-Taylor