Sending my children to a morning preschool allows me to enjoy this job of SAHM.   Both of my sons began a play-based program by age 2.   I use this time to work at my extremely part-time job, run errands, exercise, clean house, etc.  

I always felt comfortable with the providers (a neighborhood youth center similar to a YMCA and a downtown church preschool.)  Sounds like you have done plenty of research on Rory's place.  In retrospect I didn't but ended up being completely satisfied with the first 2 places I applied.    There were minor hiccups along the way ... mainly a few tears at drop off which the teachers always assured me ended as soon as I was out of sight.  For that reason I advise a habit of quick goodbyes once Rory is used to her new school.  

We have only been in morning programs.  I started gradually with 1 morning/week and now go 4x week (4 1/2 year old) and 2x week (almost 3 year old).   I alternate days so that each child also has a day home alone with me too. 1-on-1 time is so pleasant in comparison to dealing with siblings.    Even though I thought I was providing an  enriched environment at home there is so much to learn from others that I'm glad my boys get to experience time away from me with loving, qualified caregivers & new friends.  

Finally, having some time apart during the day gives us a chance to miss each other!  Good luck tomorrow and I expect you will be watching the clock and wondering what she is up to.