What to say to get her number after she jokes about meeting before the app times out

The line about the app timing out is almost always a comment on the pace of the conversation. Matches tend to fizzle in the gap between messages, and she has noticed the gap. She is not asking whether you are serious about meeting in a formal sense. She is telling you she has been waiting and that the easy thing would be to let it die.

That means the useful signal is that she is still interested enough to make the joke. If she had lost interest she would have let the thread go quiet without comment. A joke about timing out is a small invitation to show initiative. Your reply should match her energy, light and a little playful, and it should make the next move obvious.

The reply has to accomplish three things in order. First, acknowledge the joke so she knows you noticed it. Second, propose something concrete: a day, a rough time, or a place tied to something she has already said in the thread, like the bookstore. Third, make the number exchange the natural next step, not a separate request.

A specific plan lowers the cost of saying yes. A vague "we should meet sometime" gives her nothing to react to. Pick one option and offer it, with enough detail that she can accept or counter with a different time. Keep the number request short and attached to the plan, so it reads as logistics rather than a bid for her contact details.

Timing here is practical. Reply within a few hours if you can, because the joke is about momentum and a day-late answer makes the joke feel stale. If it is late at night, wait until the next day to send the plan, since a 2am message with a number request reads as more intense than the situation calls for.

If she replies with a yes and a time, move to a number exchange in the same thread or confirm the plan in a single follow-up. If she does not reply after a day, send one short message that sets a time or asks a simple question about her week, then leave it. If she still does not respond after that, stop. A second unanswered message after the plan is a sign the thread has run its course, and chasing it turns a light joke into pressure.