Live Listen is IOS, not ReSound. It doesn’t seem very discriminating, IMO. It amplifies both ambient noise and the sound I want to hear.
The Multi-mic is both a directional and omni-directional mic. It connects to T-coils. It allows me to hear sound from my computer if I connect with the right cable. It connects to my landline phone by cable. Some people use it for streaming TV sound to their ears (though I imagine Live Listen would be about as good).
A small point: I don’t pair the Multi-mic with my iphone. It’s paired with my HAs, and the HAs are paired with the phone.
ETA: I think you would want to give the multi-mic to your daughter as a unidirectional mic and raise the level of ambient sound (‘Surroundings’ in the app).
The problem for me is that one needs to use the multi-mic program to hear the multi-mic. You’ll hear your daughter much better, everything else is likely to sound worse.
I doubt that the multi-mic will work on anything but ReSound and its rebrands (Jabra, Beltone…).