From what I understand, "Jotaro" is basically the Japanese suffix for an eldest son "Taro" with a "Jo" thrown in the front. so we can probably just substitute the "Taro" suffix with something intended for daughters. The closest I can find to a female equivalent is "Hatsu," which is a unisex name. So female Jotaro would likely be named "Johatsu."

We can also use some of Jotaro's personal info to make assumptions about her other personal info. For example, Jotaro is a frikkin' 6'5" giant, which places him in roughly the 99th percentile for American adult males. Data suggests that women are usually about 5.5 inches shorter than men in the same percentile, so we can assume Johatsu would stand at roughly 5foot 11 or an even 6 feet. Furthermore, Jotaro's eright in Stardust Crusaders is 82 kg, or 181 pounds, which places him in the American 90th percentile. A 17 year old girl in the same percentile weighs 158 pounds.

So why would I care about any of this? Because traditionally, a very tall man is a point in favor for being romantically/sexually desirable, whereas a very tall woman (Johatsu would be several inches higher than the typical Japanese man, let alone her peers) is seen as intimidating to people. This means it is likely that Johatsu would NOT simply be a female version of Jotaro in that they'd have the same experiences growing up. Jotaro's annoyance towards women pestering him would not be reflected, as an example.

To be fair, Jotaro probably felt out of place being the tall kid in school