http://www.summitpost.org/the-wife/154303 &
http://www.summitpost.org/the-husband/154518:
The patriarch of the Cascades family, The Husband rises to 7524 feet and is set just west of his three ( one, two, three) bulky daughters. Just to the southeast and within yelling distance is his Wife while his only son is tucked up safe to the north. His best friend, the Bachelor, oops, I mean the bachelor, oops, dangit I mean Bachelor is on the other side of The Wife to the southeast (she likes to stay in between the bad influence). Hardly anyone seems to climb The Husband and there is no trail to the top. The summit requires a bit over a mile of cross country travel and some short Class 3/4 rock climbing but it is doable in a long day. This one would seem to be the most mysterious and remote of the "family."I haven't been here...
http://www.summitpost.org/the-brothers/517714..., but I have been here:
http://www.summitpost.org/three-sisters/174610It's subjective. If anthropomorphism/personification adds additional intensity to the feelings surrounding your experiences while on, in, thinking about, fantasizing about, or naming a mountain, so be it. Choose whichever gender label floats your boat for whatever reason(s). If you come to find that folks around you have strong reasoning contrary to the label that initially feels right to you, then decide how much the opinions of others matter and how you will proceed.
Scientifically speaking, gender/male/female is identifiable in some cases outside of the animal kingdom, but I'm not aware of that in the case of mountains.

I find that I tend to refer to a mountain or range by proper noun, or less often simply say
the mountain(s)/peak/ridge/hill. Regardless, experiences, visions, and memories of a mountain are more important to me than words I choose to try to describe them.
When the young dude at the shop referred to my truck as, "she," I found it mildly disturbing. Had he referred to a nearby mountain as, "she," I would have noted the word choice, but it would not have bothered me at all. Speaking of the two nearby mountains I frequent most, I suppose I might be able to get used to hearing Mt. Madonna called
she, and Mummy Mountain,
he.
This one's for all those romantically coming up with names for pairs like
Husband and
Wife:
He & She
He's like the wind from the mountain
She's like the high sky above
He's like an eagle there flying
She's like the sweet turtle dove.
He's like a storm o'er the oceans
She's like this springtime air
And he and she appear to be
Contented and a well married pair.
He's like the lions in the forest
She's like the deer in the shade
He's like a sun shining brightly
She's like a cool summer's glade.
He's like a wild tornado
She's like a day that's fair
And he and she are in love I can see
Contented and a well married pair.
--Woody Guthrie, Music by Hans-Eckardt Wenzel
If that's too mushy, then there's this pair:
http://www.summitpost.org/he-devil-she-devil/151965