Well, if she's pronouncing it the proper French way, it's "SELL-ee-ah". An "s" in the beginning of a French word is always pronounced like an "s". The "ei" combination is always pronounced like the "e" in "let". The double L's have a regular L sound. The "i" and "e" have regular long vowel sounds. The "e" is a bit hard to figure out, since there are many different ways "e" gets pronounced in French, with no real rules about it. However, it's definitely not "aye", as E's are only pronounced like that if they are accented. And the "r" at the end of the "ier" ending is silent. Of course, because of the corruption of languages over the years, she may not pronounce her last name like this at all. I once knew a girl whose last name was Jacques--just like the French boy name, so you'd think it was pronounced "Zhock". Nope. She pronounced it "Jakes!" Talk about screwing up a beautiful language. So it's best to ask your classmate how she pronounces her own name.