What to do if she replies sometimes but mostly ignores your messages

Go back through your thread and sort your messages into two piles, the ones she answered and the ones she did not. Don't go by how you felt about them when you sent them. Look at what they asked for. If the answered ones contained a question, a plan, or a specific detail she could react to, and the ignored ones were statements or open-ended check-ins, you have your answer about what she responds to. If the pattern is random, the timing may be the problem. Messages sent late at night or during her work hours often get pushed to the bottom and forgotten. Her replies being short is also normal. What matters is whether she ever starts a topic herself or only answers when you hand her one.

Answer whatever she said last, even if it was short, and then give her one thing to pick up. The thing you add should be specific enough that she can respond with a fact or an opinion in a few seconds. A question about a place, a plan, a choice between two options, or a story you are about to tell all work. Keep it to one thing. Two questions in one message usually means she answers neither. Skip anything that requires her to think about how she feels, because that is heavy to answer by text when she is half paying attention. Your message should be easy to finish reading and easy to answer, with nothing to decode.

Send one message and then wait. If she replies, match her energy and keep going. If she doesn't, you can send one more message a day or two later, ideally with a different kind of hook, like a link, a photo, or a plan you are actually making. Do not send a third message in a row without a reply, and do not send messages that say you noticed she went quiet. If the second message also gets nothing, let the thread rest for a week or more. When she comes back, the bar is simply to reply in a way that keeps things moving. If she never initiates and only answers when you do, you have your answer, and the thread should probably end on your side.