First, I am not well familiar with the romanized Korean system other than the modern standard one; so I cannot be fully sure of the other romanized names that you gave in the question.
To look for the significance of the Korean "hangeul", I suggest that you may consult the NAVER online-dictionary website, available at: dic.naver.com , should you have familiarity of the traditional Chinese characters (hanja). By putting a typical hangeul into the entry of "hanja dictionary" (한자사전, with an icon showing the hanja character 漢), its relevant hanja characters will then be given. By then, we are able to tell the original meaning of such hangeul words. If in doubt, please also use the wiki(dic)tionary, available at: en.wiktionary.org/wiki/Wiktionary:Main_Page , to look for relevant English meanings of a typical hanja.
For instance, by taking your name, 김은혜 , and by considering solely the hanja characters that has positive and significant meanings, we find the following information. (I refer to the wikitionary for the relevant English meanings, in order to avoid unnecessary discrepancy.)
김: 金, which containing meanings of "gold (Au)", "money" (Japanese uses it in this sense), "metal (in general)" and as a surname.
1) 銀, which containing meanings of "silver(Ag)", "cash/money", "wealth";
2) 恩, which containing meanings of "kindness", "mercy", "charity";
3) 殷, which containing meanings of "many/great", "abundant/flourishing", "blood/deep red", and as a rare surname.
1) 惠, which containing meanings of "favor", "benefit", "confer kindness";
2) 慧, which containing meanings of "bright", "intelligent/intelligence".
Hence, for the names of your pals, please kindly refer yourself through the above quoted webpages. 안녕!