My daughter's going on a farm internship in southern Arizona and she needs good farm boots.
Hoping ya'll can recommend what has worked best for you.

Leather
It breaths, allowing some moisture out. Hard work and sweat will see any boot get moist by the end of the day. Synthetics take a long time to dry out. Leather flexes and will take on a shape according to the wear and use involved. Synthetics retain their shape and end up causing blisters. Break in the leather boots by wearing them for a couple hours per day while doing some light work, walking around.
Not all leather boots are created equally. Different cuts from the hide, different tanning methods, different stitching. Those cheap leather boots you can get at the big box store for 30 bucks won't hold up. Better brand names include Justin, Wolverine, Timberland. Do you go for a $30 boot that lasts maybe 6 months or a $200 boot that lasts a couple years? I've done it both ways. Those durable, high quality boots are expensive, but your feet will thank you. If conditions are kinda nasty and would ruin boots in short order, go with the disposables for those jobs.

Steel Toe
Physical work will have the wearer kicking and dropping things. It does not take much to break a toe and a broken toe is not worth seeing a doctor, getting a cast...get the steel toes ad save a whole lot of grief.

Steel Shank
This is a steel bar in the sole of the boot. It protects the bottom of the foot when stomping and walking on rough surfaces. Makes life easy when stomping a shovel into hard ground.

Waterproof
Wet feet in boots can be tolerated for a few hours. Wet feet in boots for many hours will cause distress and can take the worker off the job. A splash here and there is expected and you'll get wet feet from time to time. For that occasional splash, swap your wet socks for new socks. Keeping your feet dry for long work days demands the boots don't allow water to seep in. I've seen guys treat their boots. In an emergency, WD-40, motor oil, even bearing grease will offer protection, but some of these solutions will wreck the boots. Your boots should be waterproofed as part of the manufacturing process. As they get scuffed and scraped, they lose that waterproofing. Google this: Nikwax

Lace Ups vs Pullups
Pullups are easy on, easy off. After a while they can lose their snugness.
Lace ups can be tightened as needed but the laces can get caught on machinery, sticks, obstacles.
My preference is and shall always be pullups. I'm just too danm clumsy, and that's on a good day.

Height
I hear Arizona is kind warm. no matter. Get the high top boots. They'll be warm but they reach above the ankle. There are low top boots out there, but if you are even a fraction as clumsy and awkward as me you'll save not one but many sprained ankles. If this is your daughter's first time in boots, she'll be awkward. Get the high tops.

Now let's talk about socks.
Heavy Duty or Industrial Strength durable socks, reinforced heel and toe. I get more holes in the toes than in the heel-moving my toes for leverage wears them through. When the heel wears out, they are finished. I like those with arch support. Some cotton in the blend makes them cozy. You'll spend 10 bucks on a decent pair of socks. Be sure to try on the boot while wearing the socks. These socks are bigger than normal crew socks and can make a pair of boots a little too snug. You might want 1/2 size larger to account for the socks. I can stand old ad beat up boots if I have my awesome socks. I tell you, I freakin LOVE my socks. I don't care about the boots. Awesome socks will make crappy boots bearable.
The socks need to be as high as the boot at least. Too short and the cuff of the boot will rub your leg.
Get extra socks so you can swap them if your feet get wet.

Oh..if you get something IN your boot, it sure is handy to be able to pull that boot off right now instead of trying to undo a whole bunch of laces which are probably covered in something prickly.

I agree with most of what Ken said, with exception of waterproof. For Arizona, I would say no waterproofing and get as breathable as possible. Waterproofing (goretex or whatever) keeps moisture IN as well so it will fill up with sweat. Not good.

Every brand that makes military boots makes an unlined breathable version for the desert. Maybe the only good thing about the war, but anyway. They are MUCH more comfortable in the heat. Buy muck boots for the rainy days.

I know this is a thread about boots, but socks go into boots too. I have tested many brands of wool sock and found defeet is the longest lasting. For temps up to 75F I use the all mountain version, higher Temps I use the aireator model. Great socks and since it's wool you can get away with wearing a pair or 2 for a week straight without stench or fungus issues.

gotta plug Darn Tough (Made in VT, USA) for socks. They're awesome. Guaranteed for life too. Got a hole in them? Mail them back, and they'll send you a new pair - just don't lose them.

For boots - I got a pair of Belleville tactical army boots a few years ago. They made it through a jungle motorcycle trip and have held up to homestead abuse beautifully.

I'm also someone who wears Darn Tough - have had some for about two years now. They've worn away a little bit, but are still very comfortable - however, I find them too warm for the summer, the one pair of "summer weight" that I have, I don't wear nearly as much as the heavier socks, because I don't find them nearly as comfortable. I wouldn't recommend Darn Tough for Arizona summer, but maybe I have unusually warm feet.

Darn Tough Socks website.

Over the winter, I tested the Darn Tough people of their promise to replace the 2 pairs of socks I managed to wear holes through, after extensive wear over approximately two years.

They did replace the socks. I had to pay shipping to their old sock trade in warehouse which was a bit expensive, but it cost less then buying two new pairs. Fellow Canadians - they let you ship your worn out socks to Vancouver, you don't have to mail them over the border to get them replaced. I emailed them first, because I really just wanted to test their customer service response time - and it was pretty good.

Next winter I'm going to have a pair of Darn Toughs go socko-a-socko against a pair of Smartwools.

I got a pair of Red Wing boots that I paid around $400 for and honestly they are JUNK. If I had not needed a pair of boots that day, and did not work at a shipyard where they have an on-base Red Wing Boot Shop, I would have bought something else. Trust me when I say this, it was sheer desperation and even now I regret it. I could go into a litany of reasons why, but will just say that I live in my boots and demand a lot out of them. Granted this is New England and not Arizona, but of all the boots I have had, Carolina wear like iron (and for those in cold climates want warm feet, the insulated ones are better than most brands) and are comfortable.

As for longevity, if you are concerned about that, it is not the boot brand itself that is at play, but if you use a boot dryer, Summer or winter, a boot dryer will extend the life of your boots. If they get wet and you put them by your rocket stove, they will shrivel up and die. Leather dislikes hot, fast heat that makes them dry out. Low, slow heat; but I recognize many are on off-grid homes and this is a luxury they cannot afford. Still it does greatly extend the life of a pair of boots.