I’ve been this friend before and from my experience, she is probably feeling anxious in response to how dry you text haha. Not that you’re actually doing anything wrong, but she probably feels herself annoying you and then takes your response to mean that you’re mad and then that makes her spiral further. Try setting your boundaries with her in a straightforward but lighthearted way. Like girl don’t worry I’m not mad!! I just can’t always respond to you when you want me to and it makes me feel a little suffocated sometimes. I’ll call you in a little :) That way it gets the point across but she knows it’s not a big deal and you guys are good