I think it's lovely!
Christiana is the only acceptable spelling IMO.
I prefer kris-tee-AHN-ah. The AN-ah one is very ugly to me.
Christiana is long, so a shorter, not ending in "A" middle name would be best.
BrookeBelleBrittGraceHopeJuneJoanneLivMarisNicoleNoelleRoseRuthRain /
RaineRachel /
RaquelSofie /
SophieSofia /
Sophia (I know, it does end in A, but I love the combo)
SimoneTamar (tah-MAHR)