What offline actually covers
Everything except the two things that genuinely need a server:
- Works offline: all logging, the timers and the Live Activity, Today, History, the charts, growth, her nap forecast (it is computed on your phone, not fetched), and the widgets.
- Needs a connection: Ask, which runs a model on a server, and syncing with another caregiver — which resumes by itself rather than asking you to do anything.
Two phones that were both offline
Each phone keeps its own entries and pushes them when it can, so a night where you logged in the nursery with no Wi-Fi and your partner logged downstairs on airplane mode ends with both sets of entries in one timeline. Every entry carries the initial of whoever logged it, so a duplicate is obvious and can be deleted.
Your data does not depend on us being up
The records live on the phone and in your own iCloud backup. You can export the lot at any time — a spreadsheet, or a zipped backup with every photo — and the privacy policy lists everyone who touches your data on the way through.