Some good recommendations here. A good Italian joint is La Tovala on Dublin road. You can find them on the web. Nice views of the river as well. Hyde park, The Fish Market, Mitchell's, Morton's, Rigsbys... hard to go wrong. The Italian restaurant by the hotels is good but not spectacular. There are many many more but you would need to be more specific!
Edit... I forgot Trattoria Roma and the long time Columbus favorite, The Refectory. If she is a shopper take her to Ocean Club at Easton... she may not come home!
http://www.trattoria-roma.com/
http://www.mitchellsoceanclub.com/
http://www.rigsbyskitchen.com/
http://www.latavola.biz/
http://therefectory.citysearch.com/
http://www.mortons.com/website/htmld.../columbus.html