Juno is lovely. Madeleine is similarly gorgeous, but I think you would likely get Mads/Maddie unless you called her Lainey from day 1.
Your other choices aren't to my taste, sorry (although the lovely Thea/Theia rather than Theodora would work very well with Juno - as both Juno and Theia were classical Goddesses).
Other ideas - Iris, Maia, Freya, Gaia, Thalia, Isolde, Sybil, Freda, Selene, Mara, Cressida, Flora, Hera, Artemis, Diana, Clio, Beatrix, Athena, Cora, Lara.
And I'd be tempted to use Georgia as the middle name to match her sister (or if braver possibly Virginia, Indiana, Louisiana, Dakota or Montana).