Ask her out when something doesn't add up

That off feeling isn't usually about her being a bad person. It's often one of these: inconsistency in how engaged she is. Avoidance of certain topics or questions. Tone shifts that don't match the conversation. Photos or early stories that don't line up with her actual energy. A vibe of performing rather than being. The thing is, all of these are testable in person. Some people text differently than they talk. Some people are anxious at first. Some are evasive about real things that matter. You can't know which until you're across from her.

Don't suddenly act super into her to override your doubt. That's backwards. Instead, keep your message straightforward and grounded. No extra enthusiasm, no desperate energy, no suddenly asking her favorite color or life dreams. You're not trying to convince yourself she's normal. You're asking her to show up. Say something direct: specific day, specific activity, something short. Coffee, drinks, a walk. Let the ask be simple enough that you're clearly not asking her to prove anything, you're just seeing if this works in real time. A good message here sounds like you meant what you said before, and now you want to check it against reality.

Send the message and give her 24 hours to respond with a yes, no, or reschedule. If she goes silent, don't follow up. Silence is an answer. If she says yes but flakes, don't wait around for a reschedule. If she says yes but keeps pushing the date back, that's a pattern and you should stop offering. If she shows up and the off feeling gets worse in person, you don't owe her a second date. The point of asking is to get out of text purgatory where you're stuck wondering. Once you know, you can move.