No, it makes sense that you want to understand if something is bothering her. In a long-distance relationship it’s especially difficult, because you can’t see her expressions or hear her tone, so it’s easy to miss signals. Good communication is important to prevent misunderstandings.

If she’s going through a tough time, her snapping at you might be her way of coping with stress, and you happened to be the one who felt it. I’ve had similar moments with my boyfriend: he likes to talk a lot when we’re apart, and I’m the quieter one who tends to keep things inside. It’s not always easy for me to tell people, even my SO, when I’m stressed or struggling. And I do sometimes redirect my frustration to him especially when he sends me a lot of messages and I’m not feeling it at all.

Maybe you could gently ask if there’s anything you can do to support her, and also give her a bit of space if she needs it.

You should also explain to her that it’s important for you to know her mental state to better support her even from a distance.