My two cents is that Malia -- the Hawaiian version of Mary -- is beautiful, but Maleah is a bit of a mishmash -- it's the beginning of Mary, plus Leah, but it doesn't have any real history as a name. So, I'd encourage Malia, which will save your friend's daughter from a lifetime of spelling hassles.
That's just me, though: I'm a fan of names with history and meaning, and I'm a stickler for correct spelling.
For middle names, what about:
Malia Rose
Malia Grace
Malia Hope
Malia Lily
Malia Tess
Malia Lani*
My college roommate was (still is) named Lani, and her sister's name is Malia. Lani is Hawaiian for heaven.
Or, for something a little more offbeat:
Malia Wren
Malia Psalm
Malia Honor
ETA: To honor the little girl's birthdate, she might also go with:
Malia Solstice (my personal favorite)
Malia June
Malia Summer