Can text evidence be disproved in court as hearsay?

[Diana B]

"The state's attorney called today and said that her lawyer will say that we can't prove it was her sending those texts"

Could be. You might try asking a technical question about whether text messages can be spoofed. (If it's possible, then that would explain why you are getting so much flack from a woman you have no real ties with.

"we literally have pages and pages and pages of text and social media evidence, they can say that we cannot ultimately prove that it was actually her and not someone else that sent those texts. :

Then you don't have evidence. That's what evidence is - anything that proves the veracity of a claimed fact. If your pages and pages of text don't prove that it was sent by this woman, then it's not evidence.

"Will she be able to get off scott-free with the hearsay defense?"

You are completely wrong about hearsay. This has nothing to do with hearsay.

Hearsay is not a defense to a criminal charge or a civil claim. Hearsay is a rule of evidence. The rules of evidence restrict your ability to offer into evidence anything depending on 1) what the evidence is and 2) what purpose you are trying to bring it in for.

Hearsay evidence is evidence in the form of statements made out of court, and you're trying to bring those statements in to prove the truth of the substance of those statements. That has nothing to do with your case.

This woman is relying on defense of reasonable doubt over evidence.