There are multiple uses for liquid oxygen, principally as rocket fuel, coolant, and feedstock for industry. And yes, she should at least learn the basics of working with undead, the basics of all the major disciplines. She might be able to get up to the point of the scrapes-and-bumps-trick, and to the point of making nice one-piece-as-if-it-grew-that-way furniture and doing slightly more sophisticated things to plants, by the end of the training. The book is called "Subtle Weave - The Fabric of the Multiverse and how to get Something From Nothing".
The Riverwalk seems to be largely a social place as well as a commercial one; There's date spots and amphitheater-type spaces and board game groups and seminars and meetups and schools and ballrooms and bars and cafes. The actual riverwalk part of the riverwalk is quiet and peaceful, a lot of winding gardens and arboretum type spaces that manage not to feel too crowded despite how many people visit them by clever use of mirrors and winding paths and such.
Her fellow Earth-import seems to be a serious introvert. A lot of these people seem to know each other very well already, and be pretty entrenched in their routines and likes, and she can sort of join them or just go her own way, but the spice store girl will chat about recipes with her and the Gardening Department that owns like two entire blocks of the place will hire her to make pretty paving stones and pots and such. Reystrom, owner of the Riverwalk, manages to badger Loril into delivering a fancy gilded invitation to her- A 'garden social' described as a party with her as the guest of honor. Or she can drop by his place for a chat instead if she wants.