It's not a glitch, it's just chance. Unless you haven't been speaking to her for so long that she's forgotten you, she can technically ping you. In my town, some villagers ping me more often than others and I don't think it depends only on friendship but go ahead and talk to her a bit more regularly (just don't overdo it).
The most you can do is use a TT method to get her out (I can share the one I use which is pretty safe). It won't make her more likely to ping because pings are random but it'll help you go through more moving requests faster.
The most you can do is use a TT method to get her out (I can share the one I use which is pretty safe). It won't make her more likely to ping because pings are random but it'll help you go through more moving requests faster.