I have concluded that Jaheria is just not a good character despite what people think. Let's consider why:
1) Druid weapons are comically bad in relation to what other weapons you get at the same time, so basically you should forget about meleeing.
2) Her proficiencies are all wrong to begin with.
3) She has 15 strength, not enough to get a strength bonus or make use of the strength-enhancing sling.
4) She has a low wisdom (13) which gives her only one or two bonus first level spells.

Ok, some of you think she's great as a druid. But compare her with Cernd, the shapeshifter:
1) Cernd is a better fighter at close range because of his werewolf form. (he tore apart the evil druid master)
2) Cernd is a much better caster, with 18 wisdom he gets 5 additional spells (2 first level and 1 more from level 2-4).
3) Cernd can have a decent armor class when you give him the +2 AC healing staff and bracers, which strangely don't count as armor (unlike with the kensai). Besides, with stone skin and the like, he shouldn't be taking damage, and he can rejuvenate with his other staff.
4) Cernd can claim the druid grove because he can reach level 14.

Not necessary true, since Jaheria is a fighter/druid (more diversified), she can wear both heavy metal armor and carry large shield, give her a good club or scimitar will make her a decent tank. And I don't think the bonus spells are really to much of a factor, since I only use insect plagues and elemental summoning from my druids most of the time, the key is choose the spells carefully. And both characters (Jaheria and Cernd) can regenerate so long as they have the right items. But I think in order for Cernd to regenerate, he needs to be "using" his staff rather than just having it sitting around in his "other weapon" slot.

Equip her with a belt of hill giant strength and a decent club, preferrably blackblood +3. Now she's doing around fifteen to twenty damange per swing and has a fighter's THAC0, and unlike Cernd, she doesn't have to shapeshift back into a normal form every three seconds when she wants to cast a spell.
Cernd can't claim the druid grove, he's an NPC.
Cernd's armour class doesn't even come within a stone's throw of Jaheira's, and his HP is terrible.
Finally, Jaheira is about a hundred times as interesting as Cernd. She has innumerable side quests and a romance string, and you can actually understand what she's saying. I'll sacrifice those first level spells for someone who can fight and tank for me as well. A pureclass druid is very much a waste since they can only get to level fourteen, at which point they still have very few spells. If you can't see why Jaheira is one of the best NPCs available, you're simply not using her properly.

But in order to make Jaheria a front line fighter you have to give her the hill giant strength girdle. It's better to give it to Keldorn or another tank who have better weapons available (especially if they dual wield).

I haven't experienced how powerful the shapeshifter is as a greater werewolf, but I suspect Cernd will be at least as good in damage output when you dress up Jaheria. The truth is anyway, I find druid's proper role is not up in the front lines where the can't cast when they get struck. I found that Jaheria was just sitting back to cast her spells, and I might as well have put a better caster in her place. Cernd shapeshifts after he has cast his spells or if the party is jumped from the rear as a defensive measure.

I think a big reason for me is her personality. She snipes at every other female in the party and is just annoying, whining, and humorless. As for the level 14 cap on pure druids, when Cernd gets long in the tooth and those insect spells get resisted a lot, I will just call on Viconia who can emerge at a high level, having never joined the party. (Or even Amoen, sigh)

Anomen.....ewwwwwww
Personally, I enjoy declaring to him that I am a force of evil in the Copper Coronet (where he leaves), then go to government district and slaughter everyone (including him) in his house.(No reputation reduction, and he is actually the one attack me first.)
Or, accept him into my party and make him fail his little paladin test.
(Yes I know I am a sick b**tard, but this is what you get for studying in accounting for 4 years)

For argument's sake, let's take my party - me, Korgan, Jaheira, Viconia, Edwin and Jan. We can ignore Jan and Edwin, since they don't require any stat-boost items to be good at what they do. Now I'll give Jaheira the girdle of hill giant strength and myself the girdle of frost giant strength later on in the game. Korgan can have the gauntlets of ogre power. Jaheira is now sitting in the front line with her fantastic armour class and iron skins doing 15-20 damage per swing and missing once in a blue moon. Korgan's either clobbering people from long range or beating them into pulp at close range; he's excellent at both, and does great damage either way. I'm doing my fighter/mage thing.
I don't make the Crom Faeyr. It's the best weapon in the game, but nobody in my party has a use for it when we'd be just as well off with two extra strength boosting items.
Even as a greater werewolf, Cernd barely ever hits. I know, I've been there.
You're still only seeing Jaheira as a druid, while I look at her as one of my fighters. Like I said, you're not using her properly.
As for her personality - everyone complains about this. I still don't see why. She doesn't whine, she didn't annoy me, and she's the only character in the game who actually laughs at the protagonist's jokes.

In both my games, with a kensai-mage and a blade, she doesn't have a place. The blade needs the girdle, and with the kensai's party, he is surrounded by other competent tanks (Yoshimo dual-classed, Keldorn, and Minsc).

That's fine. You're saying you don't use her, and I'm not going to hold that against you, but just because you don't put her in your party doesn't warrant unilaterally deciding that she's completely worthless.

Jaheria like Minsc isn't about stats and abilites, if you want the best stats build your hole group yourself, you deck out a group that can trash any NPC group. But Jaheria and many other NPC's are about the fun they add, with her bitching, trash talking, love interest it makes the game more interesting. And why are you playing for fun, or just to trash the monsters easlily.