I don´t wish to be picky but Princess and Sheikha are NOT a similar,much like Duke or Princess,These are all royal titles but they shouldn´t be confused: but being an Emirati I believed I could reply your problem about sending cards to Royals here from the U.A.E. Well It can https://dubai-royal-family-member56790.blogprodesign.com/54428138/5-simple-statements-about-prince-hamdan-royal-membership-card-explained