Is she interested if she never starts conversations on the app?

Start with how she replies, not whether she opens. Look at the last three exchanges. Does she answer your question and add something, like a place, a name, or a follow-up? Or does she reply with a single word and nothing to pick up? Length alone means little, but a reply that gives you a new thread to pull is a different signal than one that closes the topic.

Next, check the gaps. If she usually answers within a day and then the silence stretches to four or five days after your message, she is probably busy or unsure, not necessarily uninterested. If she answers quickly every time but never starts anything, she may simply be someone who waits. Her bio can help too. A profile that asks for specific things to message about gives you something concrete to build on.

A good reply has two jobs here. First, it answers what she actually said, so she feels heard and does not have to re-explain herself. Second, it gives her one open thing to respond to, usually a question about her own experience or a small opinion she can agree or disagree with. Skip any question that asks for a summary of her life. Broad questions tend to get a shrug when the conversation is already thin.

Keep your own part short. A message with three sentences and two questions makes her feel like she has to work to keep up, and people who wait to be messaged often don't want to take that on. Share one small detail about yourself, then hand the next move back. That keeps the exchange light enough that she can answer without deciding anything big.

Timing matters more than the wording here. If you sent something and she answered, wait until the next natural point, usually the following day, before you message again. Sending within an hour reads as chasing and leaves her no room to be the one who replies. Daytime, roughly late morning to early evening in her time zone, works better than late at night because that is when people tend to check messages.

If she does not answer, send one follow-up after about three days, and keep it lighter than your first message. Give her an easy way to respond without committing to anything. If there is still nothing after that, stop. Two unanswered messages with no initiation from her is a clear enough answer, and a third message usually makes the situation worse.