KI doesn't have a lot of "in between" rides--it's either the little kiddie rides or the coasters.
I would suggest either the Newport Aquarium (just minutes across the river from downtown Cincy) or the Cincinnati Museum Center.
My kids especially love the Aquarium. It has a tropical rainforest with colorful birds flying free; you can buy (cash only) a little container of sugar water, and they'll come perch on your hand and drink it. Another big hit with my girls (but costs extra) is the Penguin Encounter--you get to spend time up close with the penguins (and even pet the adults!) in a small group setting.
The Museum Center is 3 museums (children's, natural history/science, and local history) and an Omnimax, which is fantastic. My children absolutely BEG to go here (and did I mention they are adults?!). ;)
As for worship, I would recommend St.Mary's Basilica in Covington, KY. It's a sight to see, with the world's largest church stained glass window. Absolutely breathtaking. Covingting too is just minutes from downtown Cincy (which is why northern KY is often referred to as "Cincy South").
I believe Father is speaking at Xavier University? That's where my daughter goes. :)
Don't hesitiate to message me if you need more info!