Should you message her again if she doesn't reply?

Start by checking what you sent. A question about a specific place, a plan, or a shared joke gives her something easy to answer. A statement that needed no reply, or a message that was mostly about your feelings, gives her nothing to pick up. If your last message was a question she could answer in one line and she did not, that is more likely timing than disinterest. If the last message was a closing line, or you were the one who has been carrying the thread for a while, the silence means something different.

Also look at how she has been replying before this. If her replies were short all along, a short reply now is not a signal. If she was previously quick and engaged and has suddenly gone quiet for days, that is a more meaningful change. Compare her normal pattern to the current gap, not to what you hoped she would say.

A good follow-up gives her one small thing to respond to. It might be a new detail that connects to something she said, a light question with a yes or no answer, or a casual reference to a plan you already talked about. The message should be short enough that replying takes no effort and should make no demands about how she feels or what she intends. Your goal is to make answering feel normal, not to make her feel responsible for the conversation.

Avoid anything that reads as a test. Messages that point out the silence, ask if she got your last text, or hint that you are hurt will make most people less likely to reply. If the conversation was going somewhere real, a relaxed follow-up keeps that possibility open without asking her to commit to anything.

Give it at least a full day before following up, and longer if the earlier messages were slow or spread out. Sending in the evening of the same day, or the next morning after a slow reply, usually looks like pressure. Pick a time when a reply would be easy, not late at night, and do not try to time it to catch her attention.

If the second message also gets no reply, stop. One follow-up is the normal limit. Sending a third message with more emotion or more explanation does not change the situation and makes the silence harder to walk away from. Treat no response after two messages as a clear answer, even if it is not the one you wanted, and move on to someone who is actually responding.