@PotomacBobHough originates in Anglo-Saxon English and is traditionally pronounced "huff". However, Hough is also used as an alternate spelled of the Irish name Haugh, which is pronounced "how" or "haw".
There's also a French variant of Haugh, originally spelled Haueis, which comes from the German Hadewidis.
Note that all three names have different etymological origins and meanings. This isn't just a case of the same name going through spelling and pronunciation changes as it shifts languages.
My point being that unless you can actually ask the individual herself, you'll probably never know. In general, all answers are correct. What is specific to this person is unknown without talking to them.