Yes, chihuahuas lose their "baby teeth" just as humans do. Usually between the ages of 4 and 7 months. Most of the time they are swallowed by the dog... but no, it won't hurt them and they won't choke. =) Rarely do people actually find the teeth but it can happen. Since they do swallow it I don't have much advice on being able to find them... just keep close eye when she's chewing on things lol.
There are lots of things you can do to encourage that the teeth fall out on their own. If you are comfortable giving a raw bone a few times a week, that will be your best bet to give her a dental workout. A chicken neck is about the right size for a chihuahua. You can leave the meat on too; since it's primarily bone the stools will remain firm.
Recently some veterinarians are not choosing to remove the teeth too early (such as 6 months or so, when the spay/neuter usually happens); you can Google a search for more info as I don't know all the details. My previous vet did not like pulling them that young and instead waited for the dog to reach at least a year, and only after trying other natural (chewing) ways for them to fall out at home, would be comfortable pulling. Something about how it affects the way the adult teeth came in.