With a pending lawsuit, you can send subpoenas to 3rd party witnesses like call phone companies, but subpoenas often require a fairly long time to get responses to, and here, I don't see how _her_ cell phone records (or yours, for that matter) show that she borrowed _your_ phone to send herself threatening messages.
If you're going to prove your side of this story, you need to explain why you lent her your phone and why she'd go to all this trouble to fabricate this fake threat. If you're a credible witness and you can successfully attack her credibility, you can prove your side.
Your best bet may be to hire a lawyer who can greatly increase your chances of defeating her application for restraining order by presenting your side in a professional way. Hiring a lawyer signals to the judge you're serious about this, and a lawyer knows how to elicit your testimony effectively and attacks hers.
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