Using the bag phone.
I threw away the Nokia anyway and replaced it with a newer digital
handheld. This one also does not work at all in our marina. There is no digital signal where I sail so that point is moot.
There are some
handhelds that have connections for external anntenae and boosters to get up to 3 watts. You may consider one of these but then you are essentially a bag phone anyway.
You could forward her phone to your number or just call for messages I guess.
Hope this helps,
Mike
PS. The phone now works 100% of the time.