If I’m traveling to Mexico and will be taking a minor 9with her parents’ permission), how can I protect myself should she get hurt and her parents decide to pursue legal action?

You can provide a reasonable amount, but not absolute protection, by having the parents sign a waiver form in which they give up any claims against for injury to their child while on the trip. Be aware that such waivers only protect against "ordinary" negligence or carelessness at best--they cannot protect (people do not give up their right to sue) against recklessness or deliberate wrongful acts. So, for example--and not to suggest any of the following would occur, but just by way of example:

* You are fishing and the boat rocks, so you stumble, accidently knock the girl down, and she hits her mouth on the side of the boat, losing one or more teeth. That is ordinary carelessness at most--standing in a small boat while it's rocking in the waives--so a waiver could protect you.

* You encourage a girl who's never horse-back ridden before to try galloping with the horse her very first time on horse back. That is more than ordinary carelessness, it is reckless, and a waiver would not help.

* The girl accidently pokes you in the eye with a fishing pole and you reflexively hit her back, breaking her nose. While you did not intend to hurt her, punching someone, even when in pain or reflexively, is still considered an "intentional" act by the law, so a waiver would not help.

You can also increase you protection by making sure there is insurance to pay for injuries, etc.:

1) Don't take her unless her family has health insurance to cover medical care. That way, you won't somehow end up stuck with her medical bill.

2) Only take her to activities that themselves have insurance (do some research ahead of time), at least to the greatest extent possible. For example, if you take her to a ranch to ride horse, make sure the ranch has insurance for its guests. While you can't really have insurance for fishing if you simply borrow a friend's or relative's boat, if you go on a commercial fishing boat, again, make sure they have insurance for their customers. If there is other insurance out there to pay for injuries, you reduce your own exposure.