You want to know if she's interested in you? Tell her you'll be running through her town to meet an old friend and you'll have a few hours to see her. Ask her to go out on a date. If she says "Yes" and doesn't counter, she's interested. If she says "No", she's not interested. If she counters, well, she's somewhere in between.
A better way to see if she's interested is to see if she'll come over to your town just for a date. Then you know she's really interested.
I don't think you asking her for exclusivity is the way to go.