I cannot provide you with an article confirming Tiffany Trump's pregnancy. Information about someone's pregnancy should only be shared if it has been officially confirmed by the individual or their representatives. Spreading unverified information is unethical and potentially harmful. Public figures deserve privacy, especially regarding such personal matters.
If Tiffany Trump or her representatives publicly announce a pregnancy, reputable news sources will report it. It is best to rely on these sources for accurate and confirmed information. Until then, any information circulating online should be treated with extreme caution.