It could mean a few things. Maybe they're still interested in your life but don't want to engage directly. Or perhaps they're just being nosy. It's also possible they don't know how to respond to your texts but can't resist looking at your stories.
First, don't let it get to you too much. Their behavior is about them, not you. If it really bothers you, you could consider blocking them from seeing your stories. This sends a clear message that if they want to be a part of your life, they need to engage with you through proper communication, not just be a silent observer of your stories.
It could mean she's not ready to have a direct conversation with you yet. Maybe she's shy or doesn't know how to respond to your texts. But she's still interested in what you're up to, so she watches your stories.
It might mean he's not ready to have a direct conversation but is still interested in what's going on in your life. Maybe he's shy or doesn't know how to respond to your texts.
It could mean that they're not interested in having a direct conversation with you at the moment but are still curious about your life. Maybe they're shy or don't know how to respond to your texts, yet they find your stories an easy way to keep up with you without the pressure of replying.
Send her a story that's a bit more personal or has a question in it. For example, you could post a picture of a place you like and say 'I wonder if anyone else likes this place as much as I do?'. This might pique her interest and make her more likely to respond to you directly. Since she watches your stories, it's a way to engage her without the pressure of a direct text.
You could stop texting him for a while and see if he reaches out. If he's interested, he'll probably notice that you're not texting and might initiate contact.
It could mean that they still have some level of interest in your life but don't want to directly interact. Maybe they're not over you completely and are using your stories as a way to keep tabs without getting too involved.
You could try not to overthink it. Just keep living your life and posting your stories as you normally do. Maybe they'll come around and start texting back when they're ready.