What it means when she only texts back once a day

A single slow reply tells you almost nothing. What tells you something is how the replies read when they do arrive. Look at whether she asks you a question back, whether she references something specific you said, and whether her messages get longer or shorter over the week. If each reply is a real answer with a bit of herself in it, the once-a-day rhythm is probably just her schedule. If replies are clipped, she never starts a topic, and she never suggests anything, the content is saying more than the timing does. Keep a rough mental tally for about a week before you decide anything.

Also check whether the timing is consistent. Someone who replies around the same hour each day is often just batching their phone time. Random gaps of two days, then four hours, then a day, usually mean the chat is competing with other things and is not a priority yet.

When someone is replying once a day, every message you send is competing with whatever else is in their evening. The useful move is to make your message cheap to answer and worth answering. Ask one specific question with a clear answer, something like what she did that day or which of two options she'd pick. Avoid open-ended prompts that need effort to respond to, and avoid stacking two questions, because a second question can make the first one feel like homework.

Give her something to react to too. A short, true detail about your own day gives her a hook without asking her to perform. The aim is a message she can answer in under a minute while standing in a queue. That keeps the thread alive without asking her to speed up.

After you send a message that gives her an easy question, leave it. Do not follow up within a few hours, and do not send a second message the same evening. If she answers the next day, respond within a normal window and keep it light. Let the thread have its own pace rather than correcting it.

If you have sent two thoughtful messages across about a week and she has answered each one with a slow, short reply, shift the conversation toward a concrete plan. Suggest a specific time and place, so the decision is a yes or no rather than another round of chat. If she engages with the plan, the pace probably was just her style. If she stalls or deflects, you have your answer, and you can stop spending energy on the thread without drama.