Now, this is just what my grandmother told me but... The English version of the name Iva has been passed down because of Lady Godiva. If you are unfamiliar with her story, here is a little rundown courtesy of Wikipedia : she "was an English noblewoman who, according to a legend dating at least to the 13th century, rode naked – covered only in her long hair – through the streets of Coventry to gain a remission of the oppressive taxation that her husband imposed on his tenants." To thank her and preserve her dignity, everyone stayed indoors and did not watch. Everyone except peeping Tom (where we get the term) and he was stricken blind. Since then, out of gratitude, people would name their daughters Iva in honor of Lady Godiva and her selfless act. As I said, that is the story my grandmother told me. For reference my family is from England - I am named after my great grandmother Iva. My great Aunt (Iva's daughter) was Frances Iva, my aunt is named Elizabeth Iva, I'm Brooke Iva, and now I have a new niece who has Iva for her middle name! My name is very important to me - I treasure its family history. And FYI, we have all pronounced it [aiva] with the diphthong.
Iva is NOT a short form of Ivana. The male names Ivan and Ivo are two completely different names, one of Slavic and the other of Germanic origin. Iva, being the feminine form of Germanic Ivo (meaning "yew"), is NOT related to Ivana, feminine form of Slavic Ivan (cognate to John) in any way. (Yes, names can occasionaly sound similar and not be related at the same time. See eg. Eve and Evelyn for another example of the same phenomenon.) [noted -ed]
Iva wasn't my original name given by parents. I never got familiarized with my previous name and got teased by other people because of it, so I decided to change it to Iva, which sooner became my nickname. I like that name and it is commonly used in Czech Republic, not like my previous, uncommon name.
While usually thought of as a short form of Ivana or feminine form of Ivo, Iva can also derive from the name of the tree "Goat willow" or "Pussy willow" (Salix caprea) in various Slavic languages: vrba iva (Slovene, Croatian, Serbian), vrba jíva (Czech), wierzba iwa (Polish) etc.
This name is NOT a short form of IVANA! It's a name itself! (It has its own name day in the Czech Republic - December 1.) To be true - I hate when people call me Ivana.
Seems that Iva might also be used as alternative to Eva, aka Eve, from the Bible. I has similar sound qualities under certain conditions as E, and therefore is often used as a substitute.
Pronounced English, [IE-vuh], I love the name. In my opinion, you can pronounce a name in your own language as long as you don't mix up the pronunciations of two different languages.
https://www.behindthename.com/name/iva-3/top/brazil
https://pt.m.wiktionary.org/wiki/Iva
https://forebears.io/forenames/iva