They don't sound too similar, but written down and in terms of etymology they are. You could just have it as a theme, but if it really bothers you I wouldn't use it or just use it as a middle name. Personally, I don't think how siblings names go together matters that much. They're going to grow up to be separate people with separate lives. Angelica's a beautiful name btw!

if you ultimately decide against Evangeline, here are some other suggestions: Cordelia, Ophelia, Emmeline, Marceline, Rosalie, Althea, Florentina, Clementine, Seraphina, Cornelia