No, she is right. They are High Elves. All blood elves were high elves (unless they were born recently from blood elf parents but they'd be too young to be addressed yet). And they were with the alliance before they were with the horde.
I'm just going to link this because I don't want to ramble or mess things up.
I have a patch that allows me to choose high elves or blood elves when choosing characters on my server (rp server) but only other people with the patch can see it and it makes the high elves horde affiliated (not that I mind though because I love horde and a lot of my characters don't fit the normal mold of things).
/lorenerdiness