It would be good if, rather than starting a new topic, you continue to write in the one(s) you already have, since it is still about the same person.
Yes, they can work any type of job they want, part-time, full-time, temping, etc, and can volunteer or take internships.
If you want to know about studying...

they can also study part-time or full-time but will be classed as an "International student" for fees purposes. And, since they cannot claim public funds, probably won't be able to get assistance for those ESOL classes I mentioned in the other post. All colleges and universities know the rule about fees, so be prepared, if she does indeed require additional ESOL assistance (in time for her ILR).