What's your price range?
You can get a $100 bike from Wal-Mart. Or if you're looking for something more durable and as a street cruiser around the neighborhood chekc these out:
Kids:
http://www.trekbikes.com/us/en/bikes/kids/Adult Cruiser/Mountain:
http://www.trekbikes.com/us/en/bikes/mountain_hardtail/820/820/WSD= Women Specific Design.
I have the 4300 which is good mountain entry level bike. When I upgrade I will be moving to Full-Suspension. What you are looking for is any Hardtail in the 3 Series on Down.
Also, check out the Cruiser link on that website. Your wife might like those better. They have the classic look to them. Saw a ton of people riding cruiser specific bikes in Destin.
Trek bikes are great because of their range of offerings. Whatever your need/price range, they have it.
Let me know if you have any more questions.