Kimberly McCullough posted a photo of a script and tweeted the following:

"A day in the life of a soap actor. Say 'soap-y' I dare you"

General Hospital has verified her return.

There has been no specific date, but it will be over the summer.  How long?  I suspect that Robin returns to bring Jason home.  She will see Patrick and Emma.  But after that...who knows?  The character of Robin should be a presence in Port Charles, even if we don't see her, because she has a child there.

   But we don't know what has been planned by the writers.