I mean, she'd hardly even heard of the Tower before Moiraine arrived in the Two Rivers.

Then, she spent an incredibly short time as novice in the Tower, before going off on some hare-brained mission to catch Black Ajah.

At what point did she become this Crusader for the preservation of the White Tower? The pride and sentimental value she attaches to the White Tower is equivalent to that which Elayne attaches to the Lion Throne. In Elayne's case it makes sense, because the Throne of Andor lies at the heart of her ancestral heritage.

But the strong feelings Egwene has for the Tower don't make sense, from a characterisation point of view.

As a comparison, neither Moiraine nor Cadsuane, two "arch-Aes Sedai" who have been Aes Sedai far longer than Egwene, seem likely to have such strong feelings in this regard.

It's almost like Egwene was Compelled to see the battle for the Tower as the most important thing in the whole wide world. Which makes me wonder just what the role of Arangar's "headache treatments" might have been in this regard.