I also have a chihuahua. She looks at the chickens, but has not made a move on them at all. Of course she is a little on the "I'm not a dog, I'm a person" side. I did have a short lived problem with the JRT, but being a smart breed she quickly learned they were only for me to touch.
I'm willing to bet that you will enjoy every minute of it. I caution you to check out your ordinances & make sure you arent violating any. Hate for you to get attached & then have to get rid of them if the neighbors find out. (Although I hear neighbors can be 'bought' with 'free farm fresh eggs.'
Oh, I have checked the town ordinance. They don't regulate chickens here so I am well within my rights. I just hope that no one has an issue with it because I am considerate - not because they could actually do anything about it!