I hope you don't mind me jumping in:)? I found a few sites with the name Tyrel (spelled a few different ways)--most of them state that it was originally a surname, probably derived from the Old French "tirer", meaning "to pull"--it was used in the context of an animal pulling against the reins, and when applied to humans, eventually was regarded as meaning "obstinate" or "stubborn". (If I'm totally off-base, feel free to correct me;))
Hope that helped:)!
Here are a few of the sites I checked:
http://www.gwp.enta.net/irishhist.htm http://www.surnameweb.org/registry/t/y/r/tyrell.shtml http://www.tyrrells.com.au/winery/sc24.html