Someone stopped replying mid conversation? What to do next

Look at what she sent right before the gap. If her last message was a question, a joke that wants a reply, or a story she was clearly enjoying, the pause is probably logistics or distraction. If her last message was a short 'haha' or 'true' after you sent three paragraphs, the chat may already have been thinning before she left. Then check her usual pattern. Some people reply in bursts across a day and vanish for twelve hours without meaning anything. Others answer within minutes every time, so a six hour gap from them stands out. Measure the gap against her own habits, not against how anxious you feel about it. Once you know whether the chat was going somewhere or fading, you know how much effort the next message deserves.

A good follow up has three jobs. First, it points at something specific she said, so she can tell you read her messages and aren't sending a generic check in. Second, it gives her a cheap way to respond, such as a simple question she can answer in a line, or a choice between two options. Third, it lets her off the hook without you saying so. Leave out any question about why she went quiet, skip any mention of how long it's been, and don't add a request for a plan in the same message. Keep the energy close to where the chat left off. If you were teasing, keep teasing. If you were talking about her trip, circle back to the trip. The message should be easy to answer on a tired day, because that's when she'll be reading it.

Wait several hours before the first follow up, and longer if the chat was low energy to begin with. Sending something within an hour reads as anxious, even when the message itself is fine. If she's a fast replier, a full day of silence already means something. If she's slow, two or three days is normal. Send one follow up, then leave it alone. If there's still nothing after about a week, treat the thread as paused. You can come back weeks later with a fresh opener, but don't stack more messages on top of the first one. Don't post something she can see as a hint, and don't sit waiting by your phone. Put your attention on other conversations so the silence doesn't take over your week.