Future owner

You can point out to her that it's a long slow motor down the Potomac until you reach the Ches. or that one needs one leg shorter than the other for sailing since you're always healed over to one side, or that the cockpit & helm seating is usually more comfortable in a motorboat and the house is usually more spacious. Then there is also that you can always pull the throttles back on a motorboat, but you'll still only be doing 4 to 8 kts. under sail when the weather is turning bad and she wants to be home NOW. You can also point to the wonderful lightning rod (mast) sticking up or the boom waiting to clock her when you jibe.
All that said though, there is really great sailing and a great sailing community down in Annapolis.