It definitely doesn’t get added to the wand
Healing Hands applies to casting a spell; creating a wand is not casting a spell (though it does expend the spell slot, the spell isn’t cast when you do so, the slot just goes away for the day). It therefore does nothing to affect the wand directly; a cleric who uses a wand made by a healer definitely would not add the healer’s Charisma modifier to the amount healed.
It might apply to spells cast with a wand
Wand
Activation
Wands use the spell trigger activation method, so casting a spell from a wand is usually a standard action that doesn’t provoke attacks of opportunity. (If the spell being cast, however, has a longer casting time than 1 standard action, it takes that long to cast the spell from a wand.)
The rules definitely do refer to the spells coming from spells as being cast. Moreover, a cure light wounds spell cast from a wand is definitely a spell of the healing subschool, as required by Healing Hands.
The issue is this:
This bonus applies only to spells [...] that she casts as a healer, not to those that she may have by virtue of levels in another class.
What does “as a healer” mean here? The rest of the clause goes on to say that it definitely means not spells you have from cleric levels or bard levels or whatever. But a wand isn’t from levels in other classes at all. Still, the only definition I can imagine for “as a healer” is “using healer spell slots,” and a wand definitely doesn’t use those. Simply being a healer spell isn’t sufficient (or else it would affect spells from other classes), it specifically says “casts as a healer.” But on the other hand, a wand the healer made herself with spell slots from the healer class just might qualify. You’d have to ask the DM.
Ultimately, the healer is such a weak class you can allow even the most unlikely of interpretations, and it will still be weak
The healer spell list is awful; the healer can only do healing, and can’t even do that as well as the cleric. Healing Hands is a rather minor improvement after the lowest levels, since it’s a standard action to heal Cha HP; every attack deals Str damage, and warriors tend to get quite a few more of those. Straight-up ignoring the “cast as a healer” clause and allowing Healing Hands to apply to every spell that heals hit point damage, including those from items, would still leave the class quite weak.