1M&HD, I wouldn't worry about it. I have a jill that does the same and if I get a steady mark off the locater or terrier then I carry on digging even after she has moved and % of the time I recover a body. It is a bonus on deep warrens as I know once she has topped it she will resurface and I don't have to dig too deep (if she doesn't then she will have to be dug as she will stay forever... )!!
The main point is to work with what you have got and now that you know she is slaying them, you can either dig or not (in my case it depends on how deep!).
Another point is that ferreting