She wants casual with no label. How to reply without losing yourself

Read the word 'indefinitely' carefully. Most people who use it mean they do not want to plan the next few months, or they do not want the pressure of a label while they figure out how they feel. That is different from 'I will never want more with you.' You usually cannot tell which from one message. What you can tell is whether she is describing her current feelings or closing a door. Look at the rest of the conversation. Does she still make plans, reply with warmth, bring up things she wants to do with you? If so, she is probably describing a pace. If she has also pulled back on contact, the word is doing more work than she is letting on.

Also notice what she included and what she left out. Did she say why? Did she offer a reason tied to her own life, like a recent breakup or a busy stretch at work, or a reason tied to you? A reason about her own timing is a different signal from a reason about what she does not feel. Neither tells you the whole story, but both give you something to test against the next few weeks.

Your reply has to show that you understood her, that you are not blindsided, and that you know what you want. Name the arrangement back to her in one sentence so she knows you heard the specifics. Then state your own position as a fact about you, not a demand about her. Something like the fact that you want to know where things stand, or that you are seeing other people or not, depending on what is true. Keep it in the present tense and tied to your own preference.

Leave her a way out that is not an insult. The easiest version of this is an open question about pace, not a yes or no about the future. People respond better to 'what would make this feel right for you' than to 'are you ever going to be exclusive.' The first gives her room to answer honestly. The second asks her to commit to a decision she has explicitly said she is not making yet.

After you send a reply to a conversation like this, the next few days tell you more than her answer does. If she responds warmly within a day and keeps the same energy, you have a real read on her current position. If she takes a long time and replies with one short line, she is likely uncomfortable and trying to avoid the topic. Do not chase. Wait a full day before any follow-up, and make the follow-up about something other than the label, like a plan or a question about her week, so the conversation does not feel like a second round of the same argument.

If the pattern settles into her pulling back, cancelling plans, or going cold for more than a week, you have your answer even if she never states it. Stop initiating. If you are still in the arrangement, you can let it end without a speech by simply stopping, or send one short message saying you do not think this pace works for you and wish her well. Silence after a clear statement of your needs is itself a reply.