"Halt!" she squaloured spasmosidlingly.

"To say" is a perfectly fine verb, and in prose can bear the weight of any conversation. Except in highly farcical or melodramatic circumstances, characters have no reason to bark, murmur, assert, explain, rebut, query, put forward, agree, waver, conconglomerate, ricochet, or even grunt, when they can merely say.

Then again, at certain moments, a character might shout or whisper, and this information can be useful in the text.

In very few cases will "to say" need an adverb. The context of a scene, and the wording of the dialogue, tend to make adverbs pointless at best and noisy at worst. Never waste time by having a character say anything queryingly, querulously, quaveringly, callously, carelessly, combatively, or contumaciously, when attention might be better spent on making the character say something worth a font.