I can see two sides of this. Slyphie doesn't really have any friends to help her at this point. It would be foolish for her to go on her, and tbh, she kind of owes those people for taking her in while she was suffering from amnesia
Now on the other hand, she did seem a little too eager to completely throw away everything she has from back home. Perhaps she will run into Rudeus or someone and things will change.