A:AnswerOffice 365 Home can be used both online and offline. However if your files are saved on the cloud, you won't be able to update them until you are back online.
A:AnswerNo, it's even better. It means that you can share your subscription with up to 6 people who each get their own Office 365 benefits including, the ability to install Office 365 Home on as many devices as they need, 1 TB OneDrive cloud storage, access to the whole Office Suite, and all the other great features of Office 365. You can learn more about how to share your subscription here: https://aka.ms/AA4rino.
A:AnswerIf you are ok with sharing the same OneDrive Cloud Storage then you can install Office on her device with your Microsoft Account. You will install it on her device through your Microsoft Account. You can learn how to do it here: https://aka.ms/AA4rq32.