I thought the 2 lvl dip in Tempest Cleric was the most fun, unless you're already doing that with Shadowheart. Otherwise War Cleric is also fun. For her Druid spells she's basically a summons machine if you focus on that. For other spells you can prioritize things that boost those summons in the buffs, and then use your thunder and lightning damage or crowd control spells. Wildshape as a fallback HP sponge, if the gameplay there isn't as entertaining for you to lead with Wildshape. I think she's more fun as a caster, but one who can wear the heavy armor and use big shield, with her weapon for style points mostly hehe. I don't think I ever wild shaped Jaheira a single time in BG1, which is why it's a little tricky to have her always turning into the Owlbear as like her main thing for me.
I sometimes just go Panther/Tiger form even though it's mechanically not as useful generally, cause it kinda vibes like the druid Jaguar stone she could get in BG2, even though that was also a summon. In the Earlier game the Woodland Being and Woodwoad did the heavy lifting for me, then Elementals cause they can warp. She does feel like she's competing with Shadowheart to me, since they're both priests, but storywise they work pretty nicely together. It's harder to run Jaheira as a melee heavy character from fighter cause although Action surge is pretty big deal, it ends up applying better to spell actions anyway, and going up to lvl5 is rough in Fighter for the extra attack on account of the higher lvl Druid spells you'd miss out on.
War Cleric just gets the extra attack, plus sanctuary and the Deity selection, but you can also use a bow that way. I think it fits her background pretty well from BG1/2. She's a Harper, but the way bards are handled in BG3 is very much the musician archetype, which didn't really seem to fit. I think you can get something similar from the priest angle. Drums are kinda cool though, and cutting words are always entertaining, but again you get the weird split for the Druid spell list if trying to take her far enough in Bard for that to seem worthwhile. If dipping into Bard you don't really get any of the convo benefits that you would on your main, so always feels a little bit like leaving something on the table there compared to a Tav dip into Bard. I tried to make her a Ranger too, but it felt a little off, cause there were so many other Rangers in BG1/2 I remembered like stepping on toes.
To run her as Druid first thing to do when you wake up in the morning is summon the Woodland Being, Woad, Elemental, then cast Longstrider on everyone in the active party. That move alone has Jaheira already pulling her weight in every combat encounter.
Then you can use your elemental direct damage and control spells for everything else, or fallback on Wildshape with a concentration spell which is usually pretty straightforward. The 2 lvl dip into Cleric is pretty fun, because then she can Turn undead, which seems thematic for a Harper Druid to me, even though it's not usually part of their spell ability package. I think pureclass druid is easier to work with though, depending on what level you recruited her. The Big power spikes for druid hit at off levels, but feats are so useful, like I always want the feat at lvl 8 cause it's a big boost, and the main Druid power spike hits at lvl 10. As soon as you have an Elemental who can warp, that's basically Jaheira's bow right there. I think Druid combat can start to feel a bit formulaic in the endgame, but it's also where Jaheira sorta shines the most, especially if she's all super electric. I think Air Myrmidon and electric flails are are just very satisfying when they connect, which is more often than not. BG1 was pretty much Woodland being and Summon Lightning all day, so I guess it fits. Not having a proficiency with a sling feels like a bit of a miss to me, cause that was obviously a go to back in the day, but just having her hurl lightning bolts and iceknives instead is going to be better in the long run probably.
She's totally worth bringing along I think. Made the game for me compared to EA just having her along for the ride again hehe
Have fun out there!
