Is this another Tony K AI question? If so, there may be a command to instruct her to heal or not. Dunno. But you at least want to check if you commanded her to stop casting cleric spells since that is what a cleric may use instead of potions.
Otherwise, the two things that come to mind are skills and multiclassing.
IIRC she will multi to a cleric unless you instruct her to do otherwise. That could be one reason she isn't gaining her rogue skills fast enough.
Check her Disarm and Unlock skills. If they are especially low, that could be the reason she is encountering traps/locks that she can't handle (check the wiki to get an idea of typical trap/lock DCs). For some reason, the rogue henchfolk are clairvoyant and seem to know the DC of all the traps and locks and won't even attempt those beyond their skill level. Try keeping her buffed with Fox's Cunning and Cat's Grace when entering trapped/locked areas. Also, if you find any items that boost either the skills directly or the abilities (Dex/Int), try equipping her with those. Be aware, that at least as far as Dex goes, the armor may limit her skill depending on how heavy it is and how much Dex she has (max dex level). So perhaps try some lighter armor.
So, to summarize: limit cleric levels, increase Dex and Int as high as you can and try to find or buy rogue skill items for her to wear. Then just be kind to her
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