This claim is mostly false. According to Iowa State University's Archive of Women's Political Communication, she began modeling at 16 years old, though it is unsubstantiated whether or not she supported her family financially during that time. However, the other two claims made are false or difficult to find evidence for. Firstly, although Melania Trump claimed to MSNBC in 2016 that she spoke "English, Italian, French, German," and with her native Slovenian that would have been five languages, there has not been substantial proof that this is true. She has been videoed meeting French and Italian speakers, but not much can be heard beyond basic pleasantries. She also reportedly has had translators present at most meetings or relies on speaking English. She has not demonstrated proficiency in any languages other than English and Slovenian. As for the second claim, that Melania became a US citizen before meeting Donald Trump, this is false. According to the White House Historical Association, she married Donald Trump in 2005, and she did not become a citizen until 2006 (CNN).
https://www.newsweek.com/melania-trump-fluent-5-languages-what-we-know-1894733
I got the information about how many languages she speaks from this Newsweek article.
https://www.cnn.com/2023/12/15/politics/melania-trump-national-archives-speech
Information about when she became a citizen from CNN.
https://www.whitehousehistory.org/bios/melania-trump
Information about her marriage from White House Historical Association.
Bias does not really have any bearing on this information, because it is just simple facts and figures, not opinion-based journalism. That being said, CNN is usually left-leaning.