I bet she also voted in 2012 and not for Mitt Romney.
It would not be beyond the realm of believability that these “administrative errors” are tied to voters who haven’t voted in several elections (perhaps from the belief of “administrators” that the voter has moved but they’re still listed on the voting rolls - wouldn’t want that “free” vote to go inactive!).
People have been trying to clear these lists of these dead and moved voters - I’ve read of successful campaigns to do this in FL and TX.