There are several possibilities. She might be a bit shy or hesitant to reply to your text directly. Watching your story could be her way of showing some level of interest without fully engaging in a conversation. Or perhaps she was in a situation where she couldn't text back immediately, like being in a meeting or with family, but had a moment to quickly look at your story. Another reason could be that she doesn't really want to have a deep text conversation but is casually interested in your updates as shown by watching your story.
Perhaps he's a bit shy or hesitant to respond to your text directly. By watching your story, he can keep a bit of distance while still being involved. It might also be that he was in a hurry when he saw your text and only had time to quickly view your story.
Maybe she was just too busy at that time. There could be a lot of things on her plate, like work, study or taking care of family. So she might not have had the time to check your story.
Well, it might be that they're trying to keep their distance while still being a bit nosy. They didn't wish you a happy birthday because they don't want to give you the wrong idea that they want to be back in your life in a big way. But watching your story shows that they're still interested in what's going on with you on some level.
You could send her a friendly message asking if she saw it. For instance, 'Hey, I noticed you didn't watch my story. Just wanted to make sure you're okay.'
It depends on how you feel. If you think there's still a chance for a positive interaction and you really want to clear the air, you could reach out casually. But be prepared for the possibility that they might not respond well. They watched your story but didn't say happy birthday, which could mean they're not interested in a real conversation.
She was very accepting. She told me that everyone has the right to express themselves in their own way. She just asked me to be careful in public so that I don't attract too much unwanted attention.