Too late for that now. The earliest you can end this would be 5/

If you and tenant didn't do anything by 3/31, your lease should automatically becoming month to month now. You need to give her 30 day notice to end this lease. If you give notice now, lease will end on 5/31. Tell her if she doesn't sign a lease by 4/30, you want her to move out by 5/31. Do it in writing.