And she has so much content for a good party AFTER you get her, so she'd make more sense to be for everyone to recruit as otherwise for that content you have to be a evil in act 1 good in the rest and just..
MAKE HER ESCAPE IN ACT 1 AND JOIN ALL PARTIES IN ACT 2 c'mon

Minthara is the best character and she NEEDS to be recruitable if you side with the grove!
Also- I support the important thread in the suggestions: Let everyone in the Party Speak