I think this specific answerthis specific answer that I've recently seen here on SO might be helpful for you (you can read the whole post and I'm pretty sure you'll find an answer).
If you decide to eventually use JQuery anyway, I think there's a good explanation on how to use it for traversing XMLs here. However, be aware that it relies on the DOM innerHTML method and doesn't do the parsing itself, so cases such as having HTML content in your XML nodes might be problematic.
Hope this helps, Good luck!
UPDATE: I'm so sorry, I just read your question again and realized that you're not running in a browser, don't know how I missed it. In that case, I'm not completely sure my answer is very helpful any more, it's just that I'm not familiar with PhoneGap :/