Have you checked the battery in the remote ? The car battery would have to be almost totally empty for it to not have enough power to activate the centralised locking system.
Can't see how it won't open with the key. Mine does, even with the battery removed, but it's only the door that I'm unlocking that opens.
Try the passenger side lock, maybe the key/lock has been changed at some point and are no longer compatible.
Another option is to try the boot. Maybe the seats will fold forward and you can crawl in and reach the bonnet release that way. You may be able to fiddle the centre/arm rest panel as this is not held fast by a mechanical system. If you get access via the centre panel you should be able to reach the seat release buttons and fold 'em all down.
GOOD LUCK
No point trying to lift the manual doors buttons if she's deadlocked.
Thinking about it, I'm sure the owners manual advises not to use the deadlocks unless you feel it absolutely neccessary(or something like that) due to the hassle involved with your situation.