I want to make it clear that I am by no means a computer expert, but my 8-10 year old 8 GB HP Pavillion has really slowed down recently and a cooling fan keeps coming on when doing as little as surfing. And some parts, such as the graphics card, are no longer supported. So, instead of going to the Big Blue store, I went to a local computer firm and am having one custom built for me that hopefully will last me as long as needed. The computer will contain;
- an Intel i7 CPU
- 16 GB RAM (can be increased if needed)
- 500 GB SSD (I keep my image files on a 2T external hard drive)
- GeForce GTX1050 Ti graphics card, 4GB
- CD/DVD reader/recorder
- Windows 10 home premium
- At least two #3 USB ports and several #2 ports, and all the normal accessories and connections.

They will transfer the contents of my current computer and destroy the old one if I want.

I am perfectly satisfied with my fairly old 24" Samsung monitor so will continue with it for now. I'm using PS CC2019, Bridge, ACR, and Zerene on a regular basis. It was a little pricey so hope I've not made any major mistakes here.

Please don't take this as a nasty response, just an analysis of this question and your situation.

You stated that you have no prior experience with portraiture except for a class project or exercise. You don't know where the location is- how are you gonna address the lighting? Do you know what she expects? If you don't do the work, she will do a selfie? She's not interested in her high school yearbook! Bad omen! Sounds to me that you are walking into a MESS! That is unless you set the ground rules in a nice way.
Disinterested kids make for difficult portrait subjects. When they are into it and really want something special, you will have an easier job. If she enjoys the session, that helps too! Tell her the session-is gonna be fun and she will look and feel like a fashion model! It's not like going to the dentist!

Here's the part you're not gonna like: You don't really know what you are doing (yet) and what you are in for and you want to charge money for this service?

She does not want you to print the images. Chances are she will take whatever media you supply and have the badly printed and blame you for the poor results OR she will never have the printed and she and her folks will have no memories of her senior year.

Here's an idea. Charge her a minimal fee for your time or suspend or wave the sitting fee and charge her a fair price for the prints he selects. Anywhere from 3 to 5 times cost may cover your time and yield a modest profit. If you really want to do this for the experience and to help your friend, this might be your best bet. This is called working on speculation- if the work is good and the client is pleased you stand to score a nice order. It's better to work this way than to charge a ridiculously low price and garner a reputation for lowball prices and someon who gives away the files with no real compensation.

If you want to start a portrait portfolio and perhaps start a small business- start off on the right foot. Random pricing based on unknown overhead factors, profit margins and an unbusinesslike public perception of your work and pricing is bad business.

What you should be concerned with now is lighting, posing, the possibility of needed retouching, etc.

PLEASE give theses folks you "professional" advice. Digital media, unprinted, ends up in cyberspace and not in the hands of parents, grand forks and loved ones. If she does not have a nice set of senior portraits and no year book she will regret it.

56 Years in the portrait biz and still working!

If you want to get more information on senior portraits, fined me in the "Advance and Professional Portraiture" section right here on UHH!I'll tell you how to get the kids involved and enthused!

Pep Talk- You are a creative person- you can not be replaced by a kid with a cellphone. Go in there and set them straight and gain their confidence and cooperation!

I hope this helps!