Is one more try okay after she's gone quiet twice?

Two unanswered messages tell you less than they feel like they do. Look at the timeline first. If the messages were sent on the same day, or within 24 hours of each other, she may simply not have seen them yet. If there's been a gap of several days with nothing from her at all, that's a different signal. Check whether she was replying normally before this. A person who usually answers within a few hours and suddenly goes quiet is telling you something. A person who was always slow to reply is mostly doing what they always do.

Also check what the last thing she sent was. If your last message asked a question and she had already been giving short answers, the silence may be her way of closing the thread gently. If the conversation was warm and she stopped mid-flow, she may just have been pulled away. The difference shapes how much effort a third message is worth.

The follow-up has one job, which is to make it easy for her to respond. That means a single new reason to reply, something she can answer in a sentence or two without having to explain her silence. A message that refers back to something specific she mentioned earlier works better than a generic check-in. It also helps to make the message stand on its own, so she doesn't need to scroll up to understand what you're asking.

Avoid anything that asks her to justify the gap. Phrases that hint at the silence, or that make replying feel like an obligation, put her on the defensive. Keep the message light, keep it short, and make the question something she could say yes or no to without much thought. You're offering a door, not asking her to walk back through one.

Timing does more work here than wording. Send a follow-up during the part of the day when people are normally checking messages, which for most people is late morning or early evening on a weekday. Late-night messages after silence often land as either desperate or as a sign you're drinking, even if neither is true. Give it at least two or three days after your last message, and longer if the silence was already a week. Sending too soon makes the gap look like it's bothering you more than it is.

If there is still no answer after the one follow-up, that is the answer for now. Let the thread sit. You can come back to it later with a fresh reason to talk, such as a relevant link or an event you're going to, but don't send another message just to check whether she's still there. Stopping cleanly, without a passive-aggressive last text, leaves the door open for her to return on her own terms.