My 27 year old daughter does exactly the same - but hers is spelt as it should be pronounced, except the spelling is Portuguese. Which she has a grandmother who was from there, family going back generations... She goes by a very shortened version now, which she actually hates, for the sake of her own sanity.
My 19 year old son is called the longer Hebrew version of a name that is usually shortened into another name entirely in the UK. There was a row with the in-laws when his (English) grandfather (ex-FIL) essentially renamed him, he gets the "normal" version of his name's spelling from that entire side of the family and I think he was perhaps 4 or 5 when he was asked, by teachers, if he wanted to shorten his name to this other "more English" name entirely. By this point, I was "your choice" about the whole name situations.. DS said absolutely not, wouldn't answer when teachers got him muddled up with the actual other boy in the class called by the more acceptable version (but a totally different) name, and then I'd get calls and letters home about his rudeness...
Not his name, he had made his preferred name very clear (as had I), he wasn't the one being rude.
Then again, his middle name is also a surname. Guess the fun we had with that when he started school and name tags everywhere... (made by the school on coat pegs and work trays...) had his middle name as his surname. (Say, his name was Joe Smith Jones... rather than Joe Jones, his tags all read Joe Smith... that's not his name, obviously!)
(Son and I are, actually, Jewish. Ex was fine with his name - which his sister picked off the short-list, anyway, because ex and I were essentially at war over two totally separate names. Ex's parents are staunch Catholics. Which... we assumed they'd be okay, because it's a biblical name, but nope. Ex and I almost broke up when I was a week post-partum and it's the only time in 48 years that he's ever stood up to his passive-aggressive parents).
Use the pronunciation that YOU want - her name was the first gift, part of her identity, that you tangibly gave your daughter, OP. If its family mispronouncing her name... maybe consider why.