My preferences for day hiking (long!):
Asolo boots- esp for folks with high arches. Pick your favorite, but stay away from anything that does not have a full leather upper unless you are guaranteed that you will not encounter water. I like Vibram rubber soles, they last a long time and are reasonably grippy on wet rock. If you want to buy a leather conditioner there is one that looks like a jar of wax - has a blue top - that I have found works the best, sorry, can't find mine right now. I have not had good luck with the Nikwax stuff at all. Oh, and break them in BEFORE you go. This will save a lot of grief.
Smartwool socks in conjuction WITH a base layer of polypropylene sock liners- the liners act like a moleskin sheath and reduce friction between foot and sock. In addition, they are very thin so they won't muck up the sock and boot combination that you have so carefully chosen, and they also cost very little. GO with the coolmax brand liners, they are more "slippery" than the one's I see at REI.
My daypack is a Kelty, but there are LOTS of brands out there, just make sure to get one with a hip belt and support bars in the backpad. Have the salesfolks check and make sure the pack fits her body!
I use Nalgene bottles, a convenient way to get these guys to do double duty is to wrap duct tape around the middle of the bottle, that gives you some length of tape and no real addition pack space usage. I get the wide mouth variety, it is easier to clean and some water purifier adapters only fit the wide mouth. Get the Lexan variety, (clear/smoker/colored version), and buy at least four. You'll lose a few. Oh that reminds me, engrave your name on the top!!
A camelback/platypus bladder can be convient also, just stash the bladder in the pack and thread the hose around and attach to shoulder strap, but the innards can get pretty manky after a time.
I like the REI convertible pants, there have been quite a few design changes for the better since I bought my pair in 1998 (!) like gusseted pockets, pull tabs on the pockets, flap on rear pockets, but my old design pair STILL has no major tears/problems even having been to bryce, zion, grand canyon, rocky mountains, smoky mountains, olympic (seattle), yosemite, numerous climbing trips, and pierced by cacti on hunting trips and subsequently put through the REAL clothes destroyer- the washer and dryer. (Yes, the cactus poked me too).
I really would like to buy a new pair, but I have to destroy these first!!
Pick your fave top layers, most everything from major makers is really nice. Mucho choices, and fashion will likely dictate what you get here.
I agree with the goretex inner layer- esp good for windproofing. It will not come cheap, though. I really like synthetic base layers for wicking- make sure they fit SNUG, not loosely- that's how wicking works.
Buy a fleece hat if it's a gonna be cold, as well as a lightweight "floppy" nylon variety for the sun. I've got one made by columbia.
Photon II light- in green (battery lasts longest) for emergency light, otherwise the Princeton Tec Matrix 3 led system lasts 40hrs on 2 double A's and is waterproof to 1000ft (should you happen to be combination scuba/dayhiking
) It has adequate light, and longevity is the name of the game here.
Your knife of choice. I like a small pocketknife and a camping saw for firewood (fallen trees only!) + (prob not necessary if dayhiking). I used to carry my Mad Dog ATAK but I had to make up uses for it. Now it's just a small sebenza.
The big pearl of the day: the Target "Knees-ease" gardening knee pad for 5.99. This sucker is the best buy of all time. An eagle scout I used to camp with gave me the tip. It makes any sitting territory comfortable, keeps your butt clean, reduces wear on the pants, doubles as fan for campfires, whatever. Believe me, folks will make fun of you for carrying one until they are sitting on jagged pebbles and you are lounging in luxury. All for six bucks. And you never have to buy another.
Ok, that's it off the top of my head. I haven't posted for a while, but I'm bitten by the hiking bug again this week- I just got back from the Grand Canyon, took the South Kaibab trail down to the river and the Bright Angel trail up. Now that's a dayhike! *hobbles off wincing in pain*
Anybody coming to Wyoming needs to be prepared for some cold/wet weather at night or in the higher elevations year round.