How did she know the mom wasn't coming back or nearby watching her nest get raided by the well meaning but sadly misinformed human?
Too many folks try to intervene in nature and actually cause more issues than they prevented.. did you see the story about the baby bison that was "rescued" by tourist.. Just for informational purposes and food for thought before the NEXT attempted rescue... the old saying that "the road to hell was paved with good intentions" rings so true in many things in life.
https://www.cnn.com/2016/05/16/heal...alf-euthanasia-good-intention-trnd/index.html
Also.. wildlife rehab told the whole story..
invasive species... means it's taking resources away from the species that actually belong here... essentially changing our ecology forever. Cats are actually invasive as well though.. noting I have two, and YES they wreak havoc on local songbirds in addition to keeping my barn clear of rodents.
I'm not judging here, so I apologize if it comes across that way! Life is a learning adventure and we don't all hold the same perspective, thankfully.
I remove invasive plant species on a daily basis. Don't think I would be trying to save an invasive animal species... Let nature take it's course or dispatch as quickly and humanely as possible.. leave the carcass out for other wildlife to consume.
If you're gonna raise them.. you might be able to find useful info at...
https://www.audubon.org/
or..
http://ornithology.com/
Best wishes!