Now, you could give her a chance first. But. TBH. Not sure about it.
You could say "W. I've decided to talk to a L to keep S here while your gone. If you would like to reconsider it would be nice to do this without the need for a court order. However I am prepared to do whatever is necessary to protect out S."
Let others chime in on this. Not sure.
BITS
Happiness is not something ready made. It comes from your own actions.