i would hope not cause thats just pure negeligence and stupidity... if she'd know she wouldve had the moral right to protect the mundanes
Well, the people in Val Reyeaux were suspicious of Resolutionists being behind everything. I'm sure Elthina may been kept infomed, but she also saw how much power the templars had seized in three years. She probably couldn't do anything directly to Meredith, not because she's her superior, which she was, but because Meredith had the largest armed force in the city, a willingness to use it, and the paranoia to think everyone and everything was a blood mage or influenced by it by Act 3.
Heck, a pro-templar Hawke does exactly what she wants, and reports that Orsino wasn't behind Thrask's rebellion and she'll dismiss it entirely saying Hawke is a victim of blood magic.
Meredith also had a templar death squad killing non-mages in broad daylight, this shows her willingness to use her forces. Also, look at her Knight-Lieutenants and Knight-Captain.
1. Cullen, a reasonable man who shared her views on mages and blood magic and was made captain for sharing them and for his experience with Uldred, but let's face, he had three years tops as a templar when given such a grand position. His experience with tracking apostates, interrogation, or even sensing corruption like Ser Otto does at the Denerim alienage is limited at best. Not a bad templar, but an inexperienced and traumatized one.
2. Ser Kerras, a "crony of Meredith's" per Thrask in Act 1, who would slaughter every mage who hadn't surrendered by the time he arrived and Meredith would call him justified, regardless of evidence beyond the fact that they hadn't surrendered by the time he arrived, all in Act 1. This same man rapes Alain and threatens him to keep it quiet, and confirms in Act 3 that Meredith is appealing to the Divine for the Right of Annulment and going over Elthina's head, and expresses great joy in killing mages.
However, I should note that if you're a mage Hawke and have Varric b.s. to him about Hawke being an Enchanter who volunteered to help the Templars track down the apostates, he is surprisingly appreciative and thanks Hawke, and mentions that not many mages are willing to work with the templars.
3. Ser Alrik. A sadist through and through, who illegally tranquilizes mages and goes to great lengths to keep it secret, and it's heavily implied that he uses these same tranqil as sex slaves. The fact that he even proposed the Tranquil Solution, regardless of it being denied, is worthy of investigation into his character and use of his authority as a templar. Also add in that the tranquil in the courtyard are pretty open about his abuse of power. All it would take to gather evidence on him, is to count the number of tranquil, and look at the records that, we know from DAO, require both the Knight-Commander AND the First Enchanter to sign in order for it to be authorized.
Him keeping his actions secret from Meredith does not actually remove the evidence of it. All she would have to do is look at who is and isn't tranquil and look at her own records, and then investigate her own templars.
4. Ser Mettin. He only appears in Act 3 as the head of Meredith's death squad. If you play pro-templar, you can work with another templar and get a more humane templar leading the investigations into escaped apostates without killing people, but if you play pro-mage, you see him attempt to kill a cousin to a mage for the high crime of giving a badly beaten and starved family member some food and a couch to sleep on, without a trial or even presenting her to the magistrate as aiding and abetting an escaped fugitive.
Out of these Knight-Lieutenants and Captain, only the Captain is in any way reasonable, save for Kerras' surprising moment if Varric b.s.' to him, and he is traumatized, only months out of Ferelden when we meet him and already Knight-Captain, and he was promoted, as per his own codex, because of his views on mages being similar to her own.
One or two people in authority we can pass off as individuals abusing the system and keeping her in the dark. Three or four, as I have pointed out, even though Cullen isn't abusing the system at all, creates a pattern.
So we have an established pattern in the kind of people Meredith was promoting, even before she got the idol.
With this kind of pattern, Elthina may very well have been threatened had she taken action against Meredith.