I'm not particularly keen on the name myself, but I definitely think it's useable and could go mainstream. I think it has become more recognisable here since
Paloma Faith became popular, but I still don't think it's a common name.
I think it works better as a middle name:
Emmeline Paloma &hearts
Harriet PalomaJessica PalomaJessamine PalomaLilith PalomaElsabet
Paloma
Paloma RosePaloma RachelPaloma JanePaloma Tess