If using all weather to carry laptop, books, etc., could get away with one office style bag only. Or as I had on my bike when teaching school, one laptop/office type bag on one side and shopper type bag on other side. Alternately, two Ortlieb Back Rollers if she plans to tour/camp with bike or make big grocery hauls.
Ortlieb Office Bag Pannier
OFFICE-BAG
The waterproof bike briefcase with roll closure can be mounted on the right or left side of the rack. It can be quickly mounted and easily taken off the rack single-handed. The Office-Bag offers room for two large DIN A4 files (size L), office supplies, mobile etc. With the padded Notebook Sleeve (available as extra accessory) it is a perfect laptop bag (up to 15.4“). Two large 3M Scotchlite reflectors and a reflective ORTLIEB logo ensure safety in the dark and in bad weather conditions. Edge protectors and base feet on the rear and bottom ensure optimal protection of the bag. It features a padded shoulder strap for comfortable transport. The bag is available in two versions: with QL2.1 or QL3.1 mounting system
https://www.ortlieb.com/en/Office-Bag/
Ortlieb Commuter Bag M QL 2.1 Pannier - Single
https://www.rei.com/product/885306/o...pannier-single
Ortlieb Commuter City Cycling Pack
https://www.rei.com/product/102314/o...y-cycling-pack
Ortlieb Velocity Design Cycling Pack
Stylish, versatile and waterproof, the Ortlieb Velocity Design Pack is perfect for daily bike commutes in any weather
Ortlieb Vario QL2.1 Pannier - Single
https://www.rei.com/product/102315/o...n-cycling-pack
Ortlieb Vario QL2.1 Pannier - Single
The Ortlieb Vario QL2.1 is a waterproof bag that can be used as a backpack or pannier.
https://www.rei.com/product/115450/o...pannier-single
Crazy deal on this one:
Ortlieb Office-Bag High-Visibility QL3 Bag
Ortlieb Office-Bag High-Visibility QL3 Bag - Save 66%
Or,
Ortlieb Back-Roller Classic Panniers - Pair
When heading out on a weekend bike trip, keep your goods dry and protected on your rear rack in the waterproof Ortlieb Back-Roller Classic Bike Panniers.
https://www.rei.com/product/885299/o...-panniers-pair
Orliebs have served me well, long time, all conditions.